2022381375 273167

The 6th prime for this k.

779602395*2^274412-1 (82616 digits)
3467560635*2^274439-1 (82624 digits) The first prime for this K in the drive

151515*2^261867-1 (78836 digits)

26565*2^264851-1 (79733 digits)

262494705*2^287730-1
1609753035*2^293338-1
1609753035*2^296668-1
262494705*2^298772-1
262494705*2^300155-1
558796095*2^310629-1
1609753035*2^322444-1

870667875*2^276165-1 (83143 digits)

The 50th prime from the RPS drive:

1694614845*2^276735-1 (83315 digits)

151515*2^285823-1 (86047 digits)

17295*2^217577-1 (65502 digits)
17295*2^219284-1 (66016 digits)

26565*2^277766-1 (83621 digits)

869688105*2^405836-1 (122178 digits)

The 8th prime for this k in the RPS drive:

870667875*2^278560-1 (83864 digits)

From choose your own K:
759237765*2^263768-1 (79411 digits)

869688105*2^418774-1 (126073 digits)

759237765*2^268641-1 (80878 digits)

151515*2^303419-1 (91344 digits)

870667875*2^280741-1 (84521 digits)

26565*2^289274-1 (87085 digits)

151515*2^308258-1 (92801 digits)

Cruelty
 

[B]151515[/B] appears to be a good one! Several primes in a row, congrats!

But I wonder what happened to 759237765*2^268641-1. More than 2 days after the submission its verification is still [URL="http://primes.utm.edu/primes/page.php?id=76739"]In Process[/URL] :question:

[QUOTE=Kosmaj][B]151515[/B] appears to be a good one! Several primes in a row, congrats![/quote]
Yes, I'll keep my fingers crossed :smile:
BTW: I have another "fun" ideas - 12345*2^n-1 and/or 5*3^n-1. As soon as I have some free resources I will have a look at those.
[QUOTE=Kosmaj]But I wonder what happened to 759237765*2^268641-1. More than 2 days after the submission its verification is still [URL="http://primes.utm.edu/primes/page.php?id=76739"]In Process[/URL] :question:[/QUOTE]
Strange indeed, but it is mentioned there that they are unable to verify all results now - maybe we could propose them our own team-based double checking? I am already doing proth test on all of my discovered primes anyway...

I've verified 759237765*2^268641-1 using proth.
[quote]Continue: Test of file "prime.txt" at line 100, k*2^n-1.
759237765 268641
759237765*2^268641 - 1 may be prime. (a = 19)
759237765*2^268641 - 1 is prime! (P = 5, Q = -1) [80878 digits]
759237765*2^268641 + 1 factor : 7
759237765*2^268642 - 1 factor : 59
759237765*2^268640 - 1 is composite. (a = 7)
Done.[/quote]

[QUOTE=Cruelty]Strange indeed, but it is mentioned there that they are unable to verify all results now - maybe we could propose them our own team-based double checking? I am already doing proth test on all of my discovered primes anyway...[/QUOTE]

I think they mean that they can't verify all types of primes such as ones requiring the use of ECPP. There shouldn't be any problem with ours as they use LLR to verify them. I wonder if the process doing the LLR test has hung.

663301485*2^283108-1 (85233 digits)

1346178405*2^247896-1 (74634 digits)

[QUOTE=Cruelty]I've verified 759237765*2^268641-1 using proth.
Continue: Test of file "prime.txt" at line 100, k*2^n-1.
759237765 268641
759237765*2^268641 - 1 may be prime. (a = 19)
759237765*2^268641 - 1 is prime! (P = 5, Q = -1) [80878 digits]
759237765*2^268641 + 1 factor : 7
759237765*2^268642 - 1 factor : 59
759237765*2^268640 - 1 is composite. (a = 7)
Done.
[/QUOTE]

Does this mean that the number is prime or composite? I mean, one line says it is prime for something and then another says it is composite. I need to know for sure to get the count right for the DC info site. Until I get an answer I will leave it out of the count.

1952775825*2^221012-1

The earlier number posted, 759237765*2^268641 - 1, is prime.
The Proth test also tested the same number+1 and other tests
for twin primes.

17295*2^256769-1 (77300 digits)

From the RPS Drive:

918332415 282017 (84905 digits)

From the RPS drive
3467560635*2^283353-1 (85308 digits)

k=1222853775
 

From Choose your own k:

1222853775*2^262364-1 (78989 digits) is prime

k=1222853775
 

From Choose your own k:

1222853775*2^264388-1 (79598 digits) is prime:banana:

26565*2^306088-1 (92147 digits)

From the RPS drive:
1694614845*2^287699-1 (86616 digits)

From Choose your own K and sieved by Templus
226005*2^228118-1 (68676 digits)

32444271*2^403117-1 (121358 digits)

406755855*2^325509-1
262494705*2^326040-1
1756836015*2^335943-1
460292085*2^337646-1

231*2^749301-1 (225565 digits) :banana: :banana:

This should come in around #180 on the top-5000

nice

It's currently [URL="http://primes.utm.edu/primes/page.php?id=76837"]#168[/URL].

HUGE congrats! :cool:

Congratulations! :banana: :banana: :banana: Finally we have a "better" largest prime than 15k :banana: :banana: :banana:
The downside is: it will take me some time to beat it with my current k's... :squash:

Thanks. Here's another biggish one::w00t:

69*2^580596-1 (174779 digits)

212270565*2^282913-1 (85174 digits)

869688105*2^487488-1 (146758 digits)

Can I join the party? :cool:

[B]97*2^843205-1[/B] is prime! [253832 digits]

Entrance rank: 138

Congratulations! :bounce:

Very Nice:surprised

k=1222853775
 

From Choose your own k:

1222853775*2^272173-1 (81942 digits)

[QUOTE=Kosmaj][B]97*2^843205-1[/B] is prime! [253832 digits][/QUOTE]
This is quite a gap... previous prime for k=97 has been found [URL="http://primes.utm.edu/primes/page.php?id=34725"]12 years ago at n=6981[/URL] :surprised

22932195*2^217722-1 (65549 digits)

it'll be on the list for about 3 weeks :whistle:

From choose your own k:

5169615*2^267293-1 (80470 digits)

From the RPS drive:
918332415*2^294041-1 (88525 digits)

From choose your own k:

5169615*2^271290-1 (81674 digits)

97*k^n-1
 

[QUOTE=Cruelty]This is quite a gap... previous prime for k=97 has been found [URL="http://primes.utm.edu/primes/page.php?id=34725"]12 years ago at n=6981[/URL] :surprised[/QUOTE]

Guys, thanks for your kind comments. I knew that the previous prime for k=97 was at n=6981 but had no idea that it was found 12 years ago, and as I see now, by famous Mr. Dubner! It was the only [I]k[/I] with no k*2^n-1 primes for n>10000. Special thanks are due to David Broadhurst who checked k=97 in the 200-800k range, and also to Thomas Masser (60-200k) and Tom Kuechler (16-60k). The range completion details are based on Dr. Keller's [URL="http://www.prothsearch.net/riesel2.html"]records[/URL].

854917635*2^279210-1 (84060 digits)

223*2^307755-1 (92646 digits)

From the RPS drive:

2022381375 293727

22932195*2^230868-1 (69506 digits)

From Choose your own K:
2904473715*2^317447-1 (95571 digits)

151515*2^358446-1

14549535*2^244846-1 (73714 digits)

From the RPS drive

1738812075*2^295976-1 (89107 digits)

From choose your own K

22932195*2^303832-1 (91470 digits)

"My k":

445419975*2^270730-1 (81507 digits)

22932195*2^248286-1 (74749 digits)

2904473715*2^325274-1 (97927 digits)

Small but reportable

1222853775*2^224960-1 (67729 digits)

25*2^587585-1 (176883 digits)

Nice one Cruelty!

226005*2^263957-1 (79465 digits)

Thanks :smile:
I'm just trying not to stay far behind you and Kosmaj :showoff:

22932195*2^406996-1 (122526 digits)

(I have 2 machines on this - one started at 300k, the other at 400k.
Each machine found one pretty quick - 303k and this 406k. Hopefully
some of the gaps will fill in...)

2904473715*2^327844-1 (98701 digits)

247*2^952069-1 (286604 digits)

I started at n=400k for the low-weight k and hoped for 1 prime before
1M...it just made it :bounce:

Great news! Who's gonna find the first 300k digits prime?

[B]Larry[/B], congrats on a nice and big prime! :w00t: :cool: We are now 11th by score!

[B]Cruelty[/B]: Cruel to composites, gentle to primes! :smile:
Congrats on a nice k=25 prime!

Guess who's #10 :smile:
BTW: it will take me some time to find a TOP-3 RPS prime now :sad:

Time or luck. I reserved k=247 from n=400k back at the end of December.
It's a low-weight k so one machine was able to go from n=400k-1M in less
than 2 months.

How deep have you sieved your ranges for k=247, and what was the average number of candidates per 100k range of "n"? I'm just trying to compare it with my k=25, where I get 3800-4000 candidates per 100k range of "n" sieved till ~2T.

I sieved up to 700bn and only had 840 candidates per 100k. Along with
that low # of candidates per thousand is a low # of primes. The risk
of a really low-weight k like this is that you won't find *any* primes.
To find the low-weight k's for k<300, I sieved n=0-10k up to 100M.
Below is the number of candidates left, # of primes in n=0-5k, and K

[CODE]
Weight Primes K
186 7 283
185 6 269
178 7 101
176 4 29
169 6 221
146 4 251
145 8 223
130 2 239
117 3 191
116 3 127
107 5 247
53 3 253
[/CODE]

For comparison, K=25 had 582 candidates left and 21 primes. The highest
weight was K=195 with 1466 candidates and 37 primes.

From test your own k:

5169615*2^294163-1 (88559 digits)

From choose your own k - the 5th reported prime for this k
22932195*2^313832-1 (94481 digits)

Megabit
 

My first megabit prime :w00t: :cool: :banana:

[B]77*2^1467554-1[/B] (441780 digits)

After realizing that k=77 is a promising multiplier, and finding the primes at 607k (in December 2004) and 855k (in June last year) I decided to test megabit candidates working from 1M forward and from 1.5M backward. It was a time consuming "operation" but it payed off!

WTG, very nice

:w00t: Great prime Kosmaj! :bow:

Grobie and Cruelty, thanks!

Here is one more big one :w00t: :shock:
[B]2995125705*2^891645-1[/B] (268422 digits)

This one eluded us for quite a while! And it closely matches Larry's forecast (890k) based on previous largest gap.

Great primes Kosmaj!

This is the new largest gap. Duplicating the largest gap would have put this prime at n=891578!

BTW, this puts our project score ahead of 15k already. Now #3 in primes
and #10 in score.

80555475*2^281095-1 (84626 digits)

1222853775*2^249279-1 (75050 digits)

This is our 200th prime!
[CODE]
[B]Riesel Prime Search [/B]
Active primes: [B]on current list: 200[/B]; rank by number 3
Total primes: ever on any list: 217
Production score: for current list 45.307 (normalized: 1165), total 45.3206; rank by score 10
Largest prime: 77*2^1467554-1 (441780 digits) via L145 on 2/9/2006 17:11:14 CDT
Most recent: 1222853775*2^249279-1 (75050 digits) via L157 on 2/11/2006 19:21:56 CDT
Entrance Rank: mean 2657.05 (minimum 45, maximum 4824)
[/CODE]
Congrats to Grobie, and everybody else who contributed. :cool:
True, we have 5 ranked 4950-5000 that will drop from Top-5000 soon, but I'm sure they will be replaced by new ones sooner! :smile:

Thanks, 200 primes since start :banana: :banana: :banana:

Choose your own k:
k=1222853775
This makes 131 primes from n=0 to 300k

1222853775 224960 (already reported)
1222853775 249279 (already reported)

All testing from 10k to 300k is complete. Sieving to 500k in progress.

From choose your own k:

317372055*2^252736-1 (76090 digits)

k=139
 

139*2^224947-1 (67718 digits)

69*2^613781-1 (184769 digits)
8331405*2^772375-1 (232515 digits)

:shock: nice series of big primes from you and Kosmaj! Congratulations :bow:

And big primes kept on coming ... :cool:

Congrats Larry!