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Old 2017-12-10, 09:24   #166
tha
 
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Quote:
Originally Posted by axn View Post
The math is fine. I'll have to look at source to see if the code deviates from the math. It is also possible that stage 2 inadvertently picked up one 821 (especially here, since B-S degree 12 was used), but we can't reliably use it to back calculate B1/B2. A correctly implemented P1, to reliably recover this factor every time, must use B1=821^2.
from results.txt:

Code:
[Sat Dec 09 16:46:59 2017]
P-1 found a factor in stage #2, B1=350000, B2=7000000, E=12.
UID: ANONYMOUS, M22411801 has a factor: 1043187363347975865450924439 (P-1, B1=350000, B2=7000000, E=12)
The fact that it was found in stage 2 and not in stage 1 might be telling.

My guess is that the mprime/prime95 stage 2 code can do power of 2 of exponents up to the square root of B2 by cleverly picking up not only all values between square root of B1 and square root of B2 but from 2 all the way up to the square root of B2. We would need to check the mprime/prime95 code.

Last fiddled with by tha on 2017-12-10 at 09:39
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Old 2017-12-10, 10:21   #167
axn
 
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Quote:
Originally Posted by tha View Post
My guess is that the mprime/prime95 stage 2 code can do power of 2 of exponents up to the square root of B2 by cleverly picking up not only all values between square root of B1 and square root of B2 but from 2 all the way up to the square root of B2. We would need to check the mprime/prime95 code.
Checked the code. It only looks for prime products <= B1. So the explanation is stage 2 B-S extension. Note that stage 2 only needed to account for the 821. Everything else is accounted for by stage 1. With E=12, this could probably happen in any number of ways.
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Old 2018-06-17, 20:53   #168
James Heinrich
 
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Yes, if anyone's looking right now, mersenne.ca is down for maintenance, should be back up within a few minutes (or many minutes, depending on how quickly the database updates process).

edit: it should be back up. Let me know if you see anything weird since I did adjust some database table structures.

Last fiddled with by James Heinrich on 2018-06-17 at 22:19
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Old 2018-06-17, 22:48   #169
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Quote:
Originally Posted by James Heinrich View Post
Yes, if anyone's looking right now, mersenne.ca is down for maintenance, should be back up within a few minutes (or many minutes, depending on how quickly the database updates process).

edit: it should be back up. Let me know if you see anything weird since I did adjust some database table structures.

Everything looks good on my end.
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