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 2016-04-29, 00:19 #12 lalera     Jul 2003 61410 Posts hi, here are the results for carol / kynea b=74, n=20000 to 40000 (74^39227-1)^2-2 continuing
 2016-05-05, 06:23 #13 Batalov     "Serge" Mar 2008 Phi(4,2^7658614+1)/2 23·1,229 Posts After a bit of a side trip with xy-yx's, continued with the CK's search and found a slightly larger one: (20^72820-1)^2-2 (current limits are 10: [95000], 20: [74000], 30: [65000], 40: [60000])
 2016-05-05, 12:35 #14 lalera     Jul 2003 26616 Posts hi, here are the results for carol / kynea b=6, n=50000 to 100000 (6^50800+1)^2-2 continuing
 2016-05-05, 14:06 #15 lalera     Jul 2003 2×307 Posts hi, here are the results for b=70, n=1000 to 10000 no prime b=72, n=1000 to 10000 (72^1920+1)^2-2 (72^6831+1)^2-2
 2016-05-05, 15:53 #16 wombatman I moo ablest echo power!     May 2013 179610 Posts For b = 26: Tested through n=14,084 - 34,000 (would be higher, but I oversieved a bit) Primes: Code: (26^19545+1)^2-2 Continuing on to n=100,000
2016-05-05, 16:17   #17
rogue

"Mark"
Apr 2003
Between here and the

3·31·71 Posts

Quote:
 Originally Posted by wombatman For b = 26: Tested through n=14,084 - 34,000 (would be higher, but I oversieved a bit) Primes: Code: (26^19545+1)^2-2 Continuing on to n=100,000
Thanks for the update. What did you sieve to? How many tests do you have to do in that range?

 2016-05-05, 16:31 #18 wombatman I moo ablest echo power!     May 2013 22×449 Posts Sieve is to P=~3.22e12. I stopped when I saw that the seconds per factor were over 500, and I figured that the PRP tests would be faster than that. Assuming the range you're referring to is from n=34,000 to n=100,000, there are approximately 11,000 tests or so to go.
2016-05-05, 17:04   #19
rogue

"Mark"
Apr 2003
Between here and the

3·31·71 Posts

Quote:
 Originally Posted by wombatman Sieve is to P=~3.22e12. I stopped when I saw that the seconds per factor were over 500, and I figured that the PRP tests would be faster than that. Assuming the range you're referring to is from n=34,000 to n=100,000, there are approximately 11,000 tests or so to go.
Then you might have not sieved deeply enough. You probably want the removal rate to be between 1000 and 1500 seconds per factor, depending upon the hardware you are running. Also, are you using the latest cksieve? It is about 50% faster than the earlier ones.

 2016-05-05, 20:44 #20 wombatman I moo ablest echo power!     May 2013 22·449 Posts I am, yes. Current PRP tests are taking ~250 seconds per test, compared to finding factors at 500+ seconds per factor. I know that at some point it will make sense to sieve more, but I was thinking that would occur when the PRP test was in the neighborhood of the sec/factor time. Would you recommend sieving more now?
2016-05-05, 20:57   #21
rogue

"Mark"
Apr 2003
Between here and the

147138 Posts

Quote:
 Originally Posted by wombatman I am, yes. Current PRP tests are taking ~250 seconds per test, compared to finding factors at 500+ seconds per factor. I know that at some point it will make sense to sieve more, but I was thinking that would occur when the PRP test was in the neighborhood of the sec/factor time. Would you recommend sieving more now?
No. You can. See what the speed is around n=50,000. You might consider doing more sieving when you get there.

 2016-05-05, 21:20 #22 wombatman I moo ablest echo power!     May 2013 22×449 Posts Will do. Thanks.

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