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Old 2016-04-29, 00:19   #12
lalera
 
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hi,
here are the results for carol / kynea
b=74, n=20000 to 40000
(74^39227-1)^2-2
continuing
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Old 2016-05-05, 06:23   #13
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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])
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Old 2016-05-05, 12:35   #14
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hi,
here are the results for carol / kynea
b=6, n=50000 to 100000
(6^50800+1)^2-2
continuing
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Old 2016-05-05, 14:06   #15
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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
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Old 2016-05-05, 15:53   #16
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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
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Old 2016-05-05, 16:17   #17
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Quote:
Originally Posted by wombatman View Post
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?
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Old 2016-05-05, 16:31   #18
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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.
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Old 2016-05-05, 17:04   #19
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Quote:
Originally Posted by wombatman View Post
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.
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Old 2016-05-05, 20:44   #20
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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?
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Old 2016-05-05, 20:57   #21
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Quote:
Originally Posted by wombatman View Post
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.
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Old 2016-05-05, 21:20   #22
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Will do. Thanks.
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