Bases 6-32 reservations/statuses/primes - Page 76

MyDogBuster · 2010-06-02, 16:14

Sierp 15 tested n=10K-25K with the following primes found:

6598*15^11715+1
977594*15^12860+1
148548*15^13101+1
966148*15^14630+1
62900*15^16936+1
633342*15^22404+1

Range Released

gd_barnes · 2010-06-04, 11:10

R26 is at n=350K; nothing to report; continuing to n=400K.

gd_barnes · 2010-06-04, 11:35

I have completed sieving R22 & S22 for n=300K-1M to P=50T. Starting from P=7T, this was a relatively substantial effort requiring > 2 CPU months. It should be sufficient for testing both sides up to n=500K. Updated sieve files are now posted on the pages.

These are some very nice files for searching! The one k remaining for R22 that is on the recommended list at n=400K is now ready and waiting to go.

S22 is reserved by the PRPnet mini drive to n=300K but is available for n>300K. Our current plan is to switch over the mini drive to a different base at n=300K.

That's the good news. Now the bad news:

If we find no primes up to n=500K on either side, the optimal sieve depth for n=500K-1M when combining them is P>250T!

(As VBCurtis pointed out at NPLB and I subsequently confirmed with my own calculations, CPU time is actually lost if we try to break off ranges and sieve the remaining range higher if the ratio of high n to low n is <= 2. That is, unless we make the determination that the effort will not be complete before CPU/software capacity/speeds have increased substantially; something that I am a proponent of taking into consideration.) Therefore although it will probably take a little more overall CPU time, we may want to consider separating the sieves for the 2 sides since the optimal for the one k will be at least somewhat lower but more importantly will sieve far faster, which would give us a better chance of proving it in a more reasonable timeframe. 4 k's vs. 1 k is a borderline case on whether they should be sieved together.

The best thing that could happen is that we find a prime for k=4233 on the Sierp side. It is by far the highest weight of the 5 combined k's remaining. Doing so would reduce the overall optimum sieve depth quite a bit.

Gary

gd_barnes · 2010-06-14, 06:02

Reserving R22 for n=400K-500K. I'll start on it after finishing R26 to n=400K in < 1 week.

unconnected · 2010-06-20, 07:48

Reserving 404*23^n-1.

gd_barnes · 2010-06-21, 10:38

R26 is complete to n=400K; nothing to report; base released.

Cruelty · 2010-06-30, 18:32

Base=10 (Sierpinski + Riesel) tested till n=490000.

vmod · 2010-07-08, 14:41

S30 status at n=270K, no primes.

Continuing to n=300K.

Attached is the updated sieve file for n=300K-500K, sieved to P=15T.

gd_barnes · 2010-07-15, 05:35

R22 is at n=450K; nothing to report; continuing to n=500K.

kar_bon · 2010-07-16, 22:11

A quick LLR V3.8.1 test and found this:

242334*7^33795+1 is prime! Time : 19.642 sec.
242334*7^34451+1 is prime! Time : 19.627 sec.

n=30k-35k done

Verified with pfgw:

Primality testing 242334*7^33795+1 [N-1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 2
Calling Brillhart-Lehmer-Selfridge with factored part 99.98%
242334*7^33795+1 is prime! (19.1742s+0.0020s)
Primality testing 242334*7^34451+1 [N-1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 2
Running N-1 test using base 3
Calling Brillhart-Lehmer-Selfridge with factored part 99.98%
242334*7^34451+1 is prime! (43.4830s+0.0020s)

mdettweiler · 2010-07-16, 23:07

Quote:

Originally Posted by kar_bon

A quick LLR V3.8.1 test and found this:

242334*7^33795+1 is prime! Time : 19.642 sec.
242334*7^34451+1 is prime! Time : 19.627 sec.

n=30k-35k done

Verified with pfgw:

Primality testing 242334*7^33795+1 [N-1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 2
Calling Brillhart-Lehmer-Selfridge with factored part 99.98%
242334*7^33795+1 is prime! (19.1742s+0.0020s)
Primality testing 242334*7^34451+1 [N-1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 2
Running N-1 test using base 3
Calling Brillhart-Lehmer-Selfridge with factored part 99.98%
242334*7^34451+1 is prime! (43.4830s+0.0020s)

Note that LLR 3.8.1 does an N-1 test on such numbers, and therefore a second proof with PFGW is unneeded. As a general rule, whenever LLR says "x is prime!" it is a proven prime, whereas it only says "is a probable prime" otherwise.

2010-06-02, 16:14	#826
MyDogBuster May 2008 Wilmington, DE 2²×23×31 Posts	Sierp 15 tested n=10K-25K with the following primes found: 659815^11715+1 97759415^12860+1 14854815^13101+1 96614815^14630+1 6290015^16936+1 63334215^22404+1 Range Released Last fiddled with by MyDogBuster on 2010-06-02 at 16:15

2010-06-04, 11:35	#828
gd_barnes May 2007 Kansas; USA 2×41×127 Posts	I have completed sieving R22 & S22 for n=300K-1M to P=50T. Starting from P=7T, this was a relatively substantial effort requiring > 2 CPU months. It should be sufficient for testing both sides up to n=500K. Updated sieve files are now posted on the pages. These are some very nice files for searching! The one k remaining for R22 that is on the recommended list at n=400K is now ready and waiting to go. S22 is reserved by the PRPnet mini drive to n=300K but is available for n>300K. Our current plan is to switch over the mini drive to a different base at n=300K. That's the good news. Now the bad news: If we find no primes up to n=500K on either side, the optimal sieve depth for n=500K-1M when combining them is P>250T! (As VBCurtis pointed out at NPLB and I subsequently confirmed with my own calculations, CPU time is actually lost if we try to break off ranges and sieve the remaining range higher if the ratio of high n to low n is <= 2. That is, unless we make the determination that the effort will not be complete before CPU/software capacity/speeds have increased substantially; something that I am a proponent of taking into consideration.) Therefore although it will probably take a little more overall CPU time, we may want to consider separating the sieves for the 2 sides since the optimal for the one k will be at least somewhat lower but more importantly will sieve far faster, which would give us a better chance of proving it in a more reasonable timeframe. 4 k's vs. 1 k is a borderline case on whether they should be sieved together. The best thing that could happen is that we find a prime for k=4233 on the Sierp side. It is by far the highest weight of the 5 combined k's remaining. Doing so would reduce the overall optimum sieve depth quite a bit. Gary Last fiddled with by gd_barnes on 2010-06-04 at 11:40

2010-06-30, 18:32	#832
Cruelty May 2005 2³×7×29 Posts	Status report Base=10 (Sierpinski + Riesel) tested till n=490000.

2010-07-16, 22:11	#835
kar_bon Mar 2006 Germany 2²×727 Posts	S7: k=242334 A quick LLR V3.8.1 test and found this: 2423347^33795+1 is prime! Time : 19.642 sec. 2423347^34451+1 is prime! Time : 19.627 sec. n=30k-35k done Verified with pfgw: Primality testing 2423347^33795+1 [N-1, Brillhart-Lehmer-Selfridge] Running N-1 test using base 2 Calling Brillhart-Lehmer-Selfridge with factored part 99.98% 2423347^33795+1 is prime! (19.1742s+0.0020s) Primality testing 2423347^34451+1 [N-1, Brillhart-Lehmer-Selfridge] Running N-1 test using base 2 Running N-1 test using base 3 Calling Brillhart-Lehmer-Selfridge with factored part 99.98% 2423347^34451+1 is prime! (43.4830s+0.0020s)

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2010-06-04, 11:10	#827
gd_barnes May 2007 Kansas; USA 2×41×127 Posts	R26 is at n=350K; nothing to report; continuing to n=400K.

2010-06-14, 06:02	#829
gd_barnes May 2007 Kansas; USA 2·41·127 Posts	Reserving R22 for n=400K-500K. I'll start on it after finishing R26 to n=400K in < 1 week.

2010-06-20, 07:48	#830
unconnected May 2009 Russia, Moscow A21₁₆ Posts	Reserving 404*23^n-1.

2010-06-21, 10:38	#831
gd_barnes May 2007 Kansas; USA 10414₁₀ Posts	R26 is complete to n=400K; nothing to report; base released.

2010-07-15, 05:35	#834
gd_barnes May 2007 Kansas; USA 10100010101110₂ Posts	R22 is at n=450K; nothing to report; continuing to n=500K.