Mersenne.ca Status Report

[tha]

Originally Posted by axn

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:

[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.

[axn]

Originally Posted by tha

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.

[James Heinrich]

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.

[storm5510]

Originally Posted by James Heinrich

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.