[quote=VBCurtis;122218]If I understand the Riesel base 16 effort correctly, I can run the base two sieve and by extension contribute to this effort. If this is right, I'd like to reserve 443 for a regular search (base 2, not 16). I'll report both base 2 and base 16 n-values as I complete them.
I'll test it to 1200k base 2, 300k base 16.
This k is low-weight, so even this large sieve is not likely to find a prime for this k. Even if I do, the prime may not be a prime for base 16 (the power would have to be a multiple of 4 to eliminate the k, right?)
-Curtis[/quote]

You are correct. The power would have to be a multiple of 4. I show it tested to n=65K on the reservation page because it shows as tested to n=260K on RPS and Prime Search. I'm assuming that you'll start testing from n=260K base 2.

I effectively double-checked it to n=25K base 16 with the effort that Anon and I had to double-check all 300<k<=1001 up to n=100K.

I had previously said that I'll double check k=443, 1478, and 3620 up to n=65K, 65K, and 75K base 16 respectively and I'll stick with doing that after I'm done sieving team drive #2 for Riesel base 16. These are all effectively Prime Search k's and I don't trust their ranges. k=1478 and 3620 convert to k=739 and 905. k=739 must have a prime where n==1 mod 4 base 2 and k=905 must have a prime where n==2 mod 4 base 2 in order for the corresponding base 16 k to have a prime.

I'll get you reserved to n=300K for this k.


Gary

17 k's from riesel base 6
 

here the first prime:

17459*6^25627-1 is prime!

it was the 10th candidate for this k i tested!!!
now about 11400 candidates less to test upto n=1M.

riesel base 6
 

17459*6^25627-1 is prime!

another riesel base 6
 

35965*6^27098-1 is prime.

about 23100 candidates fewer to test!

the last sieve-file contains 258000 candidates for the remaining 17 k's (k=1597 and 9577 extra sieve). so after this 2nd prime there are about 223500 left!

[quote=kar_bon;122260]here the first prime:

17459*6^25627-1 is prime!

it was the 10th candidate for this k i tested!!!
now about 11400 candidates less to test upto n=1M.[/quote]

Great! Karsten, are you searching all of the other 17 k's at once? (I know you're doing the lowest 2 k's separately.) If so, when you report any prime, I'll just update all of the ranges searched to the n-value of the prime.


Thanks,
Gary

yeah, that's right. all remaining 17 k in one sieve file and llr testing.
i have to sieve much more but this was a blind shot and it works.

another one bites the dust:

110784*31^19748-1 is prime

That leaves 17 or bust :>

I decided to flood this thread:

51540*31^21120-1 is prime

Now there are 16 candidates left for Riesel base 31

Starting Sierpinski base 6
 

I will start Sierpinski base 6 and test up to n=30K, if no-one else is working on it?

[quote=geoff;122338]I will start Sierpinski base 6 and test up to n=30K, if no-one else is working on it?[/quote]


I was just thinking of that one myself but my resources are quite busy so fire away! The bases divisible by 3 generally drop the k's pretty fast so it shouldn't be too bad even with a high conjecture.

Recommendation: Run PFGW 4 times, 1 each for k == 0 mod 5, 1 mod 5, 2 mod 5, and 3 mod 5 up to n=5K-7K before eliminating multiples of 6 and sieving/LLRing. It'll make for much cleaner pfgw.out files that get pretty huge with a large conjecture such as this one has.


Gary

I am going to be a glutton for punishment and start Sierp base 19 from scratch and take all k's up to n=10K. The conjecture is k=765174. :shock:


Wish me luck! :smile:


Gary

I've gained access, at least for the short term, to a Pentium 3 1Ghz machine, and though it would probably be mediocre at best for LLR, it should do fine for sieving. I've decided to reserve Riesel Base 30 k=25 for sieving up to n=100K. (I'll be releasing it after the sieving is over.) I've started the sieve with srsieve on my main crunching machine (P4 3.2Ghz), and when it's complete to roughly 0.5-1G (it should take only a few minutes) I'll move it to the Pentium3 and sieve it with sr1sieve.

Since k=25 is a power of 5, no n divisible by 5 can be prime; thus, I'll remove such n after sieving using the method Gary suggested to me in a PM earlier. :smile:

[quote=Anonymous;122364]I've gained access, at least for the short term, to a Pentium 3 1Ghz machine, and though it would probably be mediocre at best for LLR, it should do fine for sieving. I've decided to reserve Riesel Base 30 k=25 for sieving up to n=100K. (I'll be releasing it after the sieving is over.) I've started the sieve with srsieve on my main crunching machine (P4 3.2Ghz), and when it's complete to roughly 0.5-1G (it should take only a few minutes) I'll move it to the Pentium3 and sieve it with sr1sieve.

Since k=25 is a power of 5, no n divisible by 5 can be prime; thus, I'll remove such n after sieving using the method Gary suggested to me in a PM earlier. :smile:
[/quote]


Yes it is a power of 5, but the analysis is incorrect. k=25 is a perfect square. You should remove all n divisible by 2 because 5^2=25. If it was a perfect 5th power, i.e. k=3^5=243, then you would remove all n divisible by 5.

Analysis: let k=m^2 and n=2q...so m^2*30^(2q)-1 = (m*30^q-1) * (m*30^q+1) hence all even n are composite.


Gary

To give an idea of how large:
Starting riesel 31 without thinking resulted in a file of _shrug_ 14Gb

[QUOTE=gd_barnes;122353]I was just thinking of that one myself but my resources are quite busy so fire away! The bases divisible by 3 generally drop the k's pretty fast so it shouldn't be too bad even with a high conjecture.

Recommendation: Run PFGW 4 times, 1 each for k == 0 mod 5, 1 mod 5, 2 mod 5, and 3 mod 5 up to n=5K-7K before eliminating multiples of 6 and sieving/LLRing. It'll make for much cleaner pfgw.out files that get pretty huge with a large conjecture such as this one has.


Gary[/QUOTE]

[quote=gd_barnes;122366]Yes it is a power of 5, but the analysis is incorrect. k=25 is a perfect square. You should remove all n divisible by 2 because 5^2=25. If it was a perfect 5th power, i.e. k=3^5=243, then you would remove all n divisible by 5.

Analysis: let k=m^2 and n=2q...so m^2*30^(2q)-1 = (m*30^q-1) * (m*30^q+1) hence all even n are composite.


Gary[/quote]
Oh, whoops. :smile: Thanks for correcting me. I wouldn't have wanted to accidentally remove the wrong n's! :blush:

The P3 is now happy sieving away on the k. I'm taking it up to p=600G (for an n-range of 25K-100K); is this adequate, or should I go further?

BTW, are there any other k's/bases that could especially use some presieved files? I'm thinking that this machine might be perfect for such hit-and-run sieving jobs, so I'm trying it out with this one Riesel Base 30 k.

[quote=Anonymous;122369]Oh, whoops. :smile: Thanks for correcting me. I wouldn't have wanted to accidentally remove the wrong n's! :blush:

The P3 is now happy sieving away on the k. I'm taking it up to p=600G (for an n-range of 25K-100K); is this adequate, or should I go further?

BTW, are there any other k's/bases that could especially use some presieved files? I'm thinking that this machine might be perfect for such hit-and-run sieving jobs, so I'm trying it out with this one Riesel Base 30 k.[/quote]

Without doing some testing, off the top of my head, I'd say that was a little low. Base 30 is very LARGE and sr1sieve is fast! Typically now, I'd suggest what Curtis does; to sieve entire thing, break off a lower piece, and sieve remainder but I'm sure you don't want to hassle with that with a borrowed machine. For this, just LLR a candidate at 70% of n-range, i.e. n=77.5K, and sieve until the removal rate equals the LLR time. That LLR time should be very long! With speedy sr1sieve, optimal may be P=800G-1T. P=400G-600G is good for lower bases for n=25K-100K, depending on weight and # of k's.

Late estimate without running an LLR test: I checked my results file from when I ran n=0-25K. 25*30^19391-1 LLR'd in 71.9 secs. n=19391 is about 1/4th of n=77500, which means n=77500 would LLR in 71.9 secs. x 4^2 = 1150 secs. on a Dell core duo 1.66 Ghz. When you cleaned your machine out, your timing was close to mine so you should sieve until the removal rate is around 1150 secs.

Edit: If you want to have a little fun with sieving a HUGE base that is a power of 2, try Sierp base 256 with 2 k's remaining. k=535 has been tested up to n=53.7K and k=831 has been tested up to n=12.5K. The equivalent base 2 is 8X as large. Use your judgment about what range to sieve. If sieving a very large n-range, consider sieving, breaking off, and then sieving some more.

One thing I want to do with this effort in the near future is get some k's to test that are top-5000 size for a base that is a power of 2 but that are not inordinately large (~n=400K-800K base 2 equivalent). We'll get that with the team drives when we get them all sieved to n=200K, but base 256 would be a way to get a jump start on that size of potential prime.



Gary

Reserving k=1478 and 3620 for Riesel base 16. I'll double-check them up to n=65K and 75K respectively and then take them on up to n=100K.

I'll also double check Curtis's k=443 from n=25K-65K.

The test limits came previously from the Prime Search site converted from base 2.


Gary

Status update
 

Just a short status update:
base = 18; k = 122; n ~ 140K, continuing.

Edit:
Ehh, I think, I forgot the most important detail: No primes yet :(

Update Sierpinski base 6
 

Testing is at n=8K, there are 95 candidate k left.

Adding reservations
 

Hidiho,

I've finished my range on 4233*22^n+1. I won't be continuing with it.
Some more of my ranges will finish soon. In prepration I'll take
342*27^n+1
398*27^n+1
278*30^n+1
588*30^n+1
all from 25k to 100k.

Laters, Willem.

[quote=Siemelink;122537]Hidiho,

I've finished my range on 4233*22^n+1. I won't be continuing with it.
Some more of my ranges will finish soon. In prepration I'll take
342*27^n+1
398*27^n+1
278*30^n+1
588*30^n+1
all from 25k to 100k.

Laters, Willem.[/quote]

Willem,

Just to confirm. You completed 4233*22^n+1 to n=100K and you are running both 1611*22^n+1 and 5128*22^n+1 up to n=200K. Is that correct?


Thanks,
Gary

range update
 

[QUOTE=gd_barnes;122541]Willem,

Just to confirm. You completed 4233*22^n+1 to n=100K and you are running both 1611*22^n+1 and 5128*22^n+1 up to n=200K. Is that correct?


Thanks,
Gary[/QUOTE]

Still true. The k = 1611 is at 173,000, 6000 seconds per test. k = 5128 is up to 138,000.

Laters, Willem.

706 for base 27 is done to 50k. No primes found and I'm releasing it.



-Steven

[QUOTE=sjtjung;122552]706 for base 27 is done to 50k. No primes found and I'm releasing it.
-Steven[/QUOTE]

Ok, I'll pick this one up and take it to 100k. I had sieved it before christmas before I noticed that you had reserved it.

Willem

5306*28^20994-1 is prime.

I will probably reserve more of 2036 base 9 number (if no prime will be in my range) but can then slow down on LLR testing to free upp
one older AMD PC to help on Liskovets-Gallot numbers. Maybe not wery fast PC for LLR but will do its job 24/7.
Back to this later.

One for Riesel 31:

[QUOTE]69900*31^24581-1 is prime
That leaves 15 k’s
All tested up to 26.2k[/QUOTE]

Several for Sierpinski 24:

[QUOTE]19924*24^13601+1 is prime
19769*24^13627+1 is prime
5631*24^13672+1 is prime
24736*24^13770+1 is prime
27676*24^13986+1 is prime
9476*24^14382+1 is prime
674*24^14541+1 is prime
7291*24^14718+1 is prime
30349*24^14745+1 is prime
6194*24^14989+1 is prime
4196*24^15010+1 is prime
13156*24^15010+1 is prime

That leaves 172 candidates to test.
All tested upto 15k
[/QUOTE]

Is it correct, that Sierpinski base 17, 3 k's are available?
If so: I will take it to n=100k

Sierpinski base 18 still in progress

[quote=Xentar;122669]Is it correct, that Sierpinski base 17, 3 k's are available?
If so: I will take it to n=100k

Sierpinski base 18 still in progress[/quote]

Yes they are. We'll reserve them all for you.

Be sure and get the sieved file off of the main Sierp conjecture web page. It has all 3 k's in it.


Gary

no prime in range
 

my reservation has completed.

attached is the llr output.

I *think* that's all the numbers in the range. I'm unsure because my previous computer crashed and I've had to migrate everything over to a new computer. (hence the reason it took so long as well)

5133*28^7958-1 is prime.

[QUOTE]PFGW Version 1.2.0 for Windows [FFT v23.8]

Primality testing 1291*28^22811+1 [N-1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 3
1291*28^22811+1 is prime! (310.8222s+0.0034s)

Done.[/QUOTE]

gary, you can update the minimum tested value to 22811 for all the remaining base 28 sierpinski candidates.

sierp base 28 done up to n=25121 (3 primes allready submitted)

i attach a zip with the LLR results and the sieved file for n=25k to n=50k

i release the k's

Another one down for riesel 31:

30792*31^28604-1 is prime

That leaves another 14 k’s to test.

[quote=tnerual;122732]sierp base 28 done up to n=25121 (3 primes allready submitted)

i attach a zip with the LLR results and the sieved file for n=25k to n=50k

i release the k's[/quote]

Thanks for the sieve file, tnerual. I'll add it as a link in the web page.


Gary

I'll take the files:

sieve-sierp-base16-10183.txt
sieve-sierp-base16-10947.txt

[quote=tcadigan;122793]I'll take the files:

sieve-sierp-base16-10183.txt
sieve-sierp-base16-10947.txt[/quote]

You got 'em. I'll show them as reserved to n=100K. Note that they have been searched to n=30K even though the sieved files start at n=25K so you can delete the n's below 30K.


Gary

Riesel base 16:

k=1478 and 3620 are complete to n=100K which include double-checks to n=65K and 75K respectively. No primes. I'm unreserving them.

Curtis's k=443 has completed a double-check to n=65K.


Gary

10947 prime found
 

[QUOTE=gd_barnes;122795]You got 'em. I'll show them as reserved to n=100K. Note that they have been searched to n=30K even though the sieved files start at n=25K so you can delete the n's below 30K.


Gary[/QUOTE]

10947*2^142748+1 is prime! Time: 30.257 sec.

aka 10947*16^35687+1

results file attached.

taking sieve-sierp-base16-12243.txt
continuing with other reservation

[quote=geoff;122486]Testing is at n=8K, there are 95 candidate k left.[/quote]


Geoff,

I am done with analysis on most bases for k's that are multiples of the base (MOB). We are now going to include all k's that are MOB that yield a different prime for n>=1 then k / b but we will be excluding GFN's from all consideration. For Sierp base 6, the following situations exist:

k=1296, 7776, and 46656 are GFn's without a prime and are eliminated from consideration.

k=90546 is the only k remaining at n=10K that I found that does not have a prime but whose prime will be different than k / b = 90546 / 6 = 15091. That is 15091*6^1+1 is prime.

I am assuming your total of 95 k's remaining excluded k's that are multiples of the base. So on the web pages that will be updated shortly, you'll see 96 k's remaining at n=8K.

If you could, please add k=90546 to your testing starting at n=10K. Alternatively, I can just put it on the reservation page for people to pick up at a later time.


Thanks,
Gary

[quote=michaf;122778]Another one down for riesel 31:

30792*31^28604-1 is prime

That leaves another 14 k’s to test.[/quote]

Michaf,

Keep those primes coming! :smile:

I just wanted to give you a heads up here. Beginning on Monday, the project will be including k's that are a multiple of the base (MOB) but where the k yields a different prime for n>=1 than k / b -but- it will be excluding Generalized Fermat #'s (GFn's) from all consideration.

I am doing analysis on all bases for these issues but there are a few more difficult ones that I wasn't able to do yet. Base 31 is one of them. The web pages are being updated right now.

If you would like to do some analysis on base 31 for this issue, let me know. I have found the impact to be minimal for most bases. As an example, for Sierp base 6 with a conjecture of k=174308, there were 3 GFn's without a prime that were eliminated and only ONE k remaining without a prime at n=10K that was a MOB and will yield a different prime than k / b.

I can take care of this but if you'd like to try it, that works for me. If there are any questions, let me know.


Thanks,
Gary

[quote=michaf;122592]One for Riesel 31:



Several for Sierpinski 24:[/quote]

Michaf,

I've done analysis on Sierp base 24 for k's that are multiples of the base. The only one that needs a prime is k=17496. I tested it up to n=6.5K and changed the # of k's remaining from 172 to 173.

Can you test it starting from n=6.5K? If not, I can put it up for reservation.


Thanks,
Gary

If you meant all the 0 mod 31's that I left out:
It was a massive amountof 2 numbers:
28458 --> 918
69998 --> 2258

918*31^17504-1 is prime, so 2848*31^17503-1 is prime too.

What baffles me, is that I have no record of a prime for 2258
I also have not found it in 1mod2, 1mod3 or 1mod5.

duh...just noticed that 2258*31^1-1 is prime :>
which was the problem in the first place.

So this amounts to one problematic number, I will incorporate it in my search,



[QUOTE=gd_barnes;122804]Michaf,

Keep those primes coming! :smile:

I just wanted to give you a heads up here. Beginning on Monday, the project will be including k's that are a multiple of the base (MOB) but where the k yields a different prime for n>=1 than k / b -but- it will be excluding Generalized Fermat #'s (GFn's) from all consideration.

I am doing analysis on all bases for these issues but there are a few more difficult ones that I wasn't able to do yet. Base 31 is one of them. The web pages are being updated right now.

If you would like to do some analysis on base 31 for this issue, let me know. I have found the impact to be minimal for most bases. As an example, for Sierp base 6 with a conjecture of k=174308, there were 3 GFn's without a prime that were eliminated and only ONE k remaining without a prime at n=10K that was a MOB and will yield a different prime than k / b.

I can take care of this but if you'd like to try it, that works for me. If there are any questions, let me know.


Thanks,
Gary[/QUOTE]

[quote=michaf;122837]If you meant all the 0 mod 31's that I left out:
It was a massive amountof 2 numbers:
28458 --> 918
69998 --> 2258

918*31^17504-1 is prime, so 2848*31^17503-1 is prime too.

What baffles me, is that I have no record of a prime for 2258
I also have not found it in 1mod2, 1mod3 or 1mod5.

duh...just noticed that 2258*31^1-1 is prime :>
which was the problem in the first place.

So this amounts to one problematic number, I will incorporate it in my search,[/quote]


Great! Yes, the n=1 primes are the potential problems for k * b (as well as n=2/n=3/other low primes for k * b^q).

I'll add k=69998 to the pages for Riesel base 31. Since k=2258 was eliminated immediately, I'll show k=69998 reserved by you and tested to n=0K. :smile:

Thanks for taking care of that!


Gary

12243 prime found
 

12243*2^198772+1 is prime! Time: 53.926 sec.

aka 12243*16^49693+1

results file attached.

completed reservation for 10183

no prime

results file attached.

taking:
sieve-sierp-base16-13438.txt
sieve-sierp-base16-14910.txt

Sierpinski base 6 status
 

[QUOTE=gd_barnes;122803]I am assuming your total of 95 k's remaining excluded k's that are multiples of the base. So on the web pages that will be updated shortly, you'll see 96 k's remaining at n=8K.

If you could, please add k=90546 to your testing starting at n=10K. Alternatively, I can just put it on the reservation page for people to pick up at a later time.
[/QUOTE]

Actually the 95 k remaining at n=8K includes multiples of 6. I only removed perfect powers of 6 from the original sieve.

Now 60k remain at n=25K. I should be finished to n=30K by the 17th Jan.

14910 prime found
 

14910*2^151864+1 is prime! Time: 33.493 sec.

aka 14910*16^37966+1

results file attached.

continuing existing reservation

69998*31^13618-1 is prime!
(with no other primes upto 20k)

That eliminates all MOB's for base 31 riesel.

Need some more ranges
 

Hidiho,

some of my ranges will finish this week, I'll take some more:
Riesel, for n where it is now to 100000
594*27^n-1
233*28^n-1
1422*28^n-1
2319*28^n-1
4001*28^n-1

Willem.

[quote=Siemelink;122902]Hidiho,

some of my ranges will finish this week, I'll take some more:
Riesel, for n where it is now to 100000
594*27^n-1
233*28^n-1
1422*28^n-1
2319*28^n-1
4001*28^n-1

Willem.[/quote]

All of them would be from n=25K-100K with the exception of 2319*28^n-1 and 4001*28^n-1, which would be from n=5K-100K.


G

[QUOTE=gd_barnes;122804]I am doing analysis on all bases for these issues but there are a few more difficult ones that I wasn't able to do yet. Base 31 is one of them. The web pages are being updated right now.[/QUOTE]
That's very interesting. 3 and 7 are troublesome as well. Could there be something special about Mersenne Prime bases? 3 is both a Mersenne Prime and a Fermat Prime, so if there's a connection, it's a double whammy.

5 and 17 are Fermat primes, anything going on with base 17?

[quote=jasong;122940]That's very interesting. 3 and 7 are troublesome as well. Could there be something special about Mersenne Prime bases? 3 is both a Mersenne Prime and a Fermat Prime, so if there's a connection, it's a double whammy.

5 and 17 are Fermat primes, anything going on with base 17?[/quote]


Robert demonstrated some time ago that bases where b=2^q-1 are the most problematic. I haven't looked beyond base 31 in that regard. Certainly, bases 3, 7, and 15 are the big problem children and base 31 to a lesser extent. (Bases 19 and 25 will most likely prove to be problematic also.)

Michaf has done a nice job on Riesel base 31 with a relatively high conjecture of k=134718 getting it down 14 k's remaining at n=28.9K. But the Sierp side will be a pain with a conjecture of k=6360528.

Sierp base 24 seems to be the most difficult to find primes on for some reason. With a relatively low conjecture of k=30651, it still has 173 k's remaining (> 0.5%) at n=15K. This is by far the highest percentage that I can remember of remaining k's at that level of testing. I haven't analyzed it in depth to determine why this is happening.


Gary

Happy to get riesel31 to a mere 13 primes remaining:

48212*31^30691-1 is prime

That leaves 13 k’s to test

I've now tested upto 31k

and some more fun with sierpinski 24:

21276*24^15196+1 is prime
11874*24^15419+1 is prime
28591*24^15910+1 is prime

That leaves 169 k’s to test

I’ve done upto 16.6k now, so many more to come...

[quote=gd_barnes;122806]Michaf,

I've done analysis on Sierp base 24 for k's that are multiples of the base. The only one that needs a prime is k=17496. I tested it up to n=6.5K and changed the # of k's remaining from 172 to 173.

Can you test it starting from n=6.5K? If not, I can put it up for reservation.


Thanks,
Gary[/quote]

[quote=michaf;122991]and some more fun with sierpinski 24:

21276*24^15196+1 is prime
11874*24^15419+1 is prime
28591*24^15910+1 is prime

That leaves 169 k’s to test

I’ve done upto 16.6k now, so many more to come...[/quote]


Micha,

Did you add back MOB k=17496 to Sierp base 24? I had tested it to n=6.5K with no prime and had added one to your remaining k's from before. I had assumed that you had previously removed it per the prior project description. So this would now make 170 k's remaining unless you found a prime for it.


Gary

I'm still hoping for a sieve file.

Also, I've thought about it, and I've decided I'm willing to sieve for any base from 2-31. I'm thinking I might download the various sieve files and see what kinds of numbers I come up with.

Of course, I intend to start with my already reserved number. k=16734 base=4. :)

[quote=jasong;122994]I'm still hoping for a sieve file.

Also, I've thought about it, and I've decided I'm willing to sieve for any base from 2-31. I'm thinking I might download the various sieve files and see what kinds of numbers I come up with.

Of course, I intend to start with my already reserved number. k=16734 base=4. :)[/quote]

What kind of sieving resources do you have? There are 2 'factoring holes' in the Sierp base 16 drive for n=100K-200K up to P=1T. They are at P=772.8G-800G and 976.5G-1T. After the holes are filled in , we need to take it up to P=1.5T or so.

I'm thinking to get it to 1.5T would take about 10 CPU days but just getting it to about P=1.2T-1.25T would be helpful.

I need to remove k's found prime by the drive in the last few days but I could send them to you within about 6 hours or so. (4 AM GMT)

Let me know and I'll give you more specifics about what is needed.


Gary

[QUOTE=gd_barnes;123000]What kind of sieving resources do you have? There are 2 'factoring holes' in the Sierp base 16 drive for n=100K-200K up to P=1T. They are at P=772.8G-800G and 976.5G-1T. After the holes are filled in , we need to take it up to P=1.5T or so.

I'm thinking to get it to 1.5T would take about 10 CPU days but just getting it to about P=1.2T-1.25T would be helpful.

I need to remove k's found prime by the drive in the last few days but I could send them to you within about 6 hours or so. (4 AM GMT)

Let me know and I'll give you more specifics about what is needed.


Gary[/QUOTE]
That'd be great(receiving the sieving files, I mean), I have to play catchup with some non-Mersenne forum stuff(I'm very forgetful, need to take better notes), but I ought to be able to run the sieving in the next few days, and be done in a week or so. 10 cpu days sounds pretty easy, considering I have a Core2Quad. :)

[quote=jasong;123002]That'd be great(receiving the sieving files, I mean), I have to play catchup with some non-Mersenne forum stuff(I'm very forgetful, need to take better notes), but I ought to be able to run the sieving in the next few days, and be done in a week or so. 10 cpu days sounds pretty easy, considering I have a Core2Quad. :)[/quote]

I just realized that I'll have a dual-core machine freed up later tonight. I'd like to fill in the 'factor holes' first so that it is cleanly sieved up to P=1T. That should take < 1 day. I'll then send the files to you for sieving to P=1.5T. Look for them sometime late Thurs./early Fri.

Are you familiar with how to run sr2sieve? If not, I should mention that it doesn't remove candidates, it only writes out factors. I'm fine if you want to run the sieve and send me the factors. I can then remove the candidates using srfile.


Gary

13438 prime found
 

[QUOTE=tcadigan;122856]...
sieve-sierp-base16-13438.txt
...[/QUOTE]

13438*2^395260+1 is prime! Time: 232.374 sec.

aka 13438*16^98815+1

results file attached. (file completed)

Gary can you send a pm with directions how to submit properly? I do believe it's large enough and I've never done it before...:blush:

reserving:
sieve-sierp-base28.txt

[quote=tcadigan;123020]13438*2^395260+1 is prime! Time: 232.374 sec.

aka 13438*16^98815+1

results file attached. (file completed)

Gary can you send a pm with directions how to submit properly? I do believe it's large enough and I've never done it before...:blush:

reserving:
sieve-sierp-base28.txt[/quote]


Wow, lightning strikes twice in two days! Congrats on your first top-5K prime!

And just in time before the file ran out. It saves me sieving time for n=100K-200K also. (I'm including all k's remaining in it; not just the 'team drive' k's.) Life is good! :smile:

I'm thinking it makes sense to publically post the instructions on submitting a top-5K prime. I'll do that in the 'report primes here' thread in a little while.

Edit: This one will be a little 'different' so to speak. You can choose to submit it as is but the top-5K site will 'normalize' it to 6719*2^395261+1. I would suggest submitting it in this normallized format. I prefer to do it that way because otherwise you get a cryptic message that is not an error but is hard to understand if you've never done it before. I'll send you a PM in addition to the public instructions.


Gary

No, I did not add it back (haven't even seen it coming up :>)

I'll add it to my files, and sieve/llr it as far as the rest

[QUOTE=gd_barnes;122993]Micha,

Did you add back MOB k=17496 to Sierp base 24? I had tested it to n=6.5K with no prime and had added one to your remaining k's from before. I had assumed that you had previously removed it per the prior project description. So this would now make 170 k's remaining unless you found a prime for it.


Gary[/QUOTE]

Status update Sierp b17 and b18
 

Sierp b17: LLR around n~90k for all three k. I reserved till 100,000, but I think I will continue. Will start sieving soon, but have a question again.
What's more effective:
- Sieve all three k together, or alone? Alone, I can use sr1sieve, which is much faster..
- Sieve n = 100,000 - 200,000, or should I already sieve a bigger range (for example 100,000 - 1,000,000)?

Sierp b18: LLR around n~150k, still one k remaining, and still no prime :(

342*27^36291+1 is prime.

found PRP by LLR, proven with pfgw. I won't continue that range obviously.
Has anyone ever found a PRP that turned out not to be prime after all?

Willem.

Usually, taking a bigger range doesn't affect the speed too much.
Then again, whenever you find a prime, the extra time is 'wasted'.

I'd say that after n=0-100k, a good choice would be n=100-500k.

Best would be to test-sieve a few ranges and see how it affects the speed

[quote=Siemelink;123060]342*27^36291+1 is prime.

found PRP by LLR, proven with pfgw. I won't continue that range obviously.
Has anyone ever found a PRP that turned out not to be prime after all?

Willem.[/quote]

Excellent! Only one k to go on Sierp base 27. If you knock that one out, it could be our first proof of a conjecture!

I know I haven't found a PRP to be not prime.

Edit: I think there is some smaller ones listed on the top-5000 site. Supposedly the larger the PRP, the less chance it has of being not prime. I heard someone say that there's a much better chance of a hardware error causing an incorrect prime than a PRP being found not prime.


Gary

[quote=michaf;123073]Usually, taking a bigger range doesn't affect the speed too much.
Then again, whenever you find a prime, the extra time is 'wasted'.

I'd say that after n=0-100k, a good choice would be n=100-500k.

Best would be to test-sieve a few ranges and see how it affects the speed[/quote]


Agreed on the range to sieve. The speed varies by the square root of the n-range so n=100K-500K should sieve about 50% slower [1-1/sqrt(100K/400K)] than n=100K-200K. If you don't want that kind of slowdown, you could do n=100K-300K, which should sieve about 29% slower [1-1/sqrt(100K/200K)]. The main thing here is that on these low-weight k's, the chance of finding a prime in any n=2X range, i.e. n=100K-200K, is well under 50% so the bigger range is better. Clearly you'll want to break off pieces of the range and LLR them as you go while continuing to sieve the higher ranges.

About how to sieve: For 2 k's, you would generally use 2 instances of sr1sieve. But for 3 to ~50-100 k's, use sr2sieve on all of them. >~50-100 k's use srsieve for all sieving. There may be exception situations on 2 or 3 k's since that's kind of the dividing line on what to use. But sr1sieve running 1 k would have to be 3X as fast as sr2sieve running 3 k's, which seems unlikely in most situations. You might test it out to be sure and post back here what you find out.


Gary

[QUOTE=gd_barnes;123017]I just realized that I'll have a dual-core machine freed up later tonight. I'd like to fill in the 'factor holes' first so that it is cleanly sieved up to P=1T. That should take < 1 day. I'll then send the files to you for sieving to P=1.5T. Look for them sometime late Thurs./early Fri.

Are you familiar with how to run sr2sieve? If not, I should mention that it doesn't remove candidates, it only writes out factors. I'm fine if you want to run the sieve and send me the factors. I can then remove the candidates using srfile.


Gary[/QUOTE]
That'd be great. Thanks. And yes, I do know how to run sr2sieve.

I've removed factors in the past using srsieve, it's simply a matter of carefully reading the instructions. :)

[QUOTE=Siemelink;123060]342*27^36291+1 is prime.

found PRP by LLR, proven with pfgw. I won't continue that range obviously.
Has anyone ever found a PRP that turned out not to be prime after all?

Willem.[/QUOTE]
I'm not familiar with the actual math, but I've heard that the bigger the number, the less likely it is to be a PRP that's not prime. In terms of the top-5000, it's probably next to impossible.

As Dr. Silverman would say: "Trust, but verify."(This applies to my assertion about PRPs, as well as the PRP itself)

Riesel Base 30 k=25 sieving status: Currently at about 340G, planning to go to 600G. Should be done sometime next week (hopefully). It's running on an older machine that isn't on all the time.

Sierp base 16 single-k reservations...
 

Reserving Riesel base 16 k=2297, 2993, and 13854. I'll take them up to n=100K. If I find one for k=13854, that'll knock out the same k on base 4.

If someone reserves Riesel base 4 k=13854, please let me know and we'll coordinate. My LLRing for base 16 to n=100K will have the effect of testing all of the even n's for base 4 up to n=200K.

In this situation, I would usually suggest reserving and testing base 4 to n=200K to accomplish finishing both of them more easily but I figure I'll do it this way and knock both of them out if I find a prime.


Gary

My 2nd Drive file will probably be done sometime tomorrow, so when that's done, I've decided I'll try some sieving for a change. :smile: I've decided to reserve the following Sierpinski Base 6 k's for sieving:
154797*6^n+1
157473*6^n+1
166753*6^n+1
168610*6^n+1
172257*6^n+1
I'm reserving all five of them for sieving in the range 30K<n<100K. After sieving I'll donate most, possibly all, of the sieved files for public consumption. (I'm considering keeping one or two of them for myself.)

Edit: Forgot to mention, I plan to sieve these up to p=600G.

[quote=Anonymous;123202]My 2nd Drive file will probably be done sometime tomorrow, so when that's done, I've decided I'll try some sieving for a change. :smile: I've decided to reserve the following Sierpinski Base 6 k's for sieving:
154797*6^n+1
157473*6^n+1
166753*6^n+1
168610*6^n+1
172257*6^n+1
I'm reserving all five of them for sieving in the range 30K<n<100K. After sieving I'll donate most, possibly all, of the sieved files for public consumption. (I'm considering keeping one or two of them for myself.)

Edit: Forgot to mention, I plan to sieve these up to p=600G.[/quote]
Hey Gary, it looks like you made an error on the Sierp. Base 6 page: You marked one more k than I had mentioned above as reserved by me. I didn't reserve 151003, just the above listed. :smile:

reservation complete
 

[QUOTE=tcadigan;123020]
...
reserving:
sieve-sierp-base28.txt[/QUOTE]

no primes found.

attached is results file.

reserving sieve-riesel-base13.txt

Two small successes for Sierpinski 24:

20161*24^16932+1 is prime
26801*24^17390+1 is prime

Including the MOB that leaves 168 sequences to eliminate (no prime upto 34.3K)

I've now included the MOB into the main files.

Ok people, I made some performance tests for sieving sierp-base 17.

The software I used:
Windows XP Pro 32 bit
srsieve 0.6.10
sr1sieve 1.2.6
sr2sieve 1.6.18

hardware:
Intel C2D E6600 @2.4 GHz


results:
First, I used srsieve to create a sieve file and sieve it till p=1G. n-range = 100,000 - 1,000,000
srsieve started with ~800 kp/s. At the end, it got ~930 kp/s

Then I used srfile to convert this sieve file to ABCD format (for use with sr2sieve) and three NewPGen files (for use with sr1sieve)

sr1sieve (single k): the speed varied between 6.8 Mp/s and 7.5 Mp/s
sr2sieve (all three k together): speed between 2.7 MP/s and 3.2 MP/s

I think, it varies so much, because it was refreshed for every factor found (almost every second), but I can say, that sieving all three k together is faster, than every k alone.

Now try sr2sieve 1.7.5 version....

sr2sieve 1.7.5: ~3Mp/s too

Status on Riesel base 16 reservations...
 

k=2297 @ n=80K
k=2993 @ n=75K
k=13854 @ n=85K

Status on my reservation for new Sierp base 19:
That is currently on hold. I think there were something like 2000+ k's remaining at n=3.5K :yucky: and it was just crawling along! I'll pick that one up again in late Jan./early Feb.


Gary

[quote=gd_barnes;123253]Status on my reservation for new Sierp base 19:
That is currently on hold. I think there were something like 2000+ k's remaining at n=3.5K :yucky: and it was just crawling along! I'll pick that one up again in late Jan./early Feb.[/quote]
You know, you could aways simply crunch it just enough to get it up to a more "round-numbered" n-value, then release it, and list all 2000 k's on their own page--then later, when you're ready to do more, you could reserve some of them if you wanted to. I guess it would take quite a while to make the web page for it, though. :sad:

BTW: I'm almost done sieving the 5 Sierp. Base 6 k's that I'd reserved. They should be done sometime around mid-day tomorrow. I've decided I'll keep two of them for PRP testing; I haven't decided which ones, yet.

after some PM with Gary,

i will start sierpinski base 31 from scratch ... conjoncture is at 6360528 so i will have a lot of test to do :smile:

PFGW script question
 

From the instructions:

(2) When starting a new base, you'll want to use PFGW using a script
Here is a cut-and-paste of one I used for base 30 Sierp:

ABC2 $a*30^$b+1 // {number_primes,$a,1}
a: from 1 to 866
b: from 1 to 5000

If I read this well, the script will still try the trivial k's. For b = 30 that's not too bad: k = = 28 mod 29. But for odd bases the trivial k == 1 mod 2 covers 50%. How do I get that in the script?

ABC2 $a*3^$b+1 // {number_primes,$a,1}
a: from 2 to 1000 step 2
b: from 1 to 5000

does not parse. I've poked around a bit but have no clue at the moment.
Anyone?

Willem.

[QUOTE=Siemelink;123264]From the instructions:

(2) When starting a new base, you'll want to use PFGW using a script
Here is a cut-and-paste of one I used for base 30 Sierp:

ABC2 $a*30^$b+1 // {number_primes,$a,1}
a: from 1 to 866
b: from 1 to 5000

If I read this well, the script will still try the trivial k's. For b = 30 that's not too bad: k = = 28 mod 29. But for odd bases the trivial k == 1 mod 2 covers 50%. How do I get that in the script?

ABC2 $a*3^$b+1 // {number_primes,$a,1}
a: from 2 to 1000 step 2
b: from 1 to 5000

does not parse. I've poked around a bit but have no clue at the moment.
Anyone?

Willem.[/QUOTE]

did you delete the pfgw.ini file ?

in fact, to start a new base, you need only 3 files in your pfgw directory (move all others to a "doc" directory)
the 3 files are[LIST=1][*]winpfgw.exe[*]install (not sure it's needed)[*]script.txt (your own script)[/LIST]
hope this help you

I just realised I only PM'd Gary about me starting the riesel side of base 24...

With a quite low conjecture it'll turn out to be a behemoth :>
432 candidates left at n=3300 :>

One comfort: it'll give quite a lot of primes above n=5k :)

Sierpinski Base 6
 

Sieving has been completed on my five reserved Sierp. Base 6 k's:
154797
157473
166753
168610
172257
I sieved up to p=600G for the range 30K<n<100K. I'm keeping 168610 and 172257 reserved for PRP testing; I'm releasing the rest. The sieve files for 154797, 157473, and 166753 are attached.

[quote=Siemelink;123264]From the instructions:

(2) When starting a new base, you'll want to use PFGW using a script
Here is a cut-and-paste of one I used for base 30 Sierp:

ABC2 $a*30^$b+1 // {number_primes,$a,1}
a: from 1 to 866
b: from 1 to 5000

If I read this well, the script will still try the trivial k's. For b = 30 that's not too bad: k = = 28 mod 29. But for odd bases the trivial k == 1 mod 2 covers 50%. How do I get that in the script?

ABC2 $a*3^$b+1 // {number_primes,$a,1}
a: from 2 to 1000 step 2
b: from 1 to 5000

does not parse. I've poked around a bit but have no clue at the moment.
Anyone?

Willem.[/quote]


You have to run multiple modulos for many bases. For instance, for Sierp base 31, you have to eliminate 1 mod 2, 2 mod 3 and 4 mod 5. Then it's just a matter of getting the LCM of 2, 3, and 5, i.e. 30, and eliminating the values that have at least one of the conditions. I had Tnueral run:

k == 0, 6, 10, 12, 16, 18, 22, and 28 mod 30

So k == 6 mod 30 for Sierp base 31 would be coded as:

ABC2 $a*31^$b+1 // {number_primes,$a,1}
a: from 6 to xxxxx step 30
b: from 1 to 5000

So, you would have 8 scripts to run for Sierp base 31.

I'm not sure what you meant by it 'does not parse'. The script that you show for base 3 should run just fine; only testing even candidates.

It's tricky when starting a new base. Between trivial and algebraic factors as well as multiples of the base, it's easy to end up testing far more than you need to. But not all MOB without a prime can be eliminated. Only the ones where k / base is still remaining.


Gary

sierpinski base 31

all k tested up to n=580 ...
14326 k left

i continue on this case !

Status on Riesel base 16 reservations...
 

Riesel base 16, k=2297, 2993, and 13854 complete to n=100K. No primes.

I am unreserving them.

Status update Sierp b17 and b18
 

b17:
yeah, great timing: two hours ago, the sieving till 1T for the next range (n 100,000 - 1,000,000) was finished, and now PRP till n = 100,000 is done.
Still no prime :(

b18:
PRP still around n = 150,000 - I am sieving at the moment.

[quote=jasong;122994]I'm still hoping for a sieve file.

Also, I've thought about it, and I've decided I'm willing to sieve for any base from 2-31. I'm thinking I might download the various sieve files and see what kinds of numbers I come up with.

Of course, I intend to start with my already reserved number. k=16734 base=4. :)[/quote]

Jasong,

Apparently we don't have any sieved files for k=16734. We're you still planning to test it?

Jean Penne effectively tested it to n=131022 base 4 with the Riesel base 2 odd-n effort for k=8367.

I missed the connection there in showing the testing limits on the web pages. I'm correcting those now.

Edit: If still planning to test it, do you have an idea of how far are you planning to take it?


Jean,

As Jasong begins testing k=16734 base 4 above n=131022, you can update your corresponding test ranges on the Riesel base 2 odd-n effort for k=8367.


Gary

Sierpinski Base 6 k=168610 has been tested up to n=100K, no primes found. I'm releasing this k. lresults for n=30K-100K are attached.

Status report on Sierp. Base 6 k=172257: currently at about 80.9K, still working on it.

Captured another one
 

594*27^36624-1 is prime.

found PRP by LLR, proven with pfgw. I won't continue that range.

Willem.

reserved ranges completed
 

I've completed 706*27^n-1 and 194 & 404*23^n-1 for all n until 100,000. No primes were found. I won't continue these pairs.

Willem.

Reserving the following Sierp. Base 6 k's for LLRnet:
154797
157473
166754
LLRnet will take these three k's up to n=100K (the end of the sieve files available). :smile:

[quote=Anonymous;123742]Reserving the following Sierp. Base 6 k's for LLRnet:
154797
157473
166754
LLRnet will take these three k's up to n=100K (the end of the sieve files available). :smile:[/quote]
Never mind, we're not reserving these k's for LLRnet after all. :smile: