mersenneforum.org Te$ting billion digit number$
 Register FAQ Search Today's Posts Mark Forums Read

2019-06-24, 07:39   #12
paulunderwood

Sep 2002
Database er0rr

333910 Posts

Quote:
 Originally Posted by hansl OK, i'm ~70% done with 75-76. And I've started 77-78 and 78-79 on other boxes. BTW, I can't wait to upgrade one of my workstations. I recently ordered parts to take it from 6C/12T up to (dual socket) 24C/48T ... 4x the cores
Opened another box with 79 to 80 bits.

2019-06-24, 08:40   #13
paulunderwood

Sep 2002
Database er0rr

333910 Posts

Quote:
 Originally Posted by paulunderwood Opened another box with 79 to 80 bits.
76-77 done. No factors.

Doing 80-81 bits now.

2019-06-24, 14:28   #14
hansl

Apr 2019

3158 Posts

Quote:
 Originally Posted by paulunderwood 76-77 done. No factors. Doing 80-81 bits now.
No factors from 75-76 (not sure if you saw in my previous edited post)
No factors from 77-78
No factors from 78-79

With that I'm done with this diversion for now; back to my regularly scheduled crunching.

 2019-06-25, 06:21 #15 paulunderwood     Sep 2002 Database er0rr 32·7·53 Posts M58133053441 has no factors below 2^81. There is not much hope that this number can be LL/PRP'ed in the near future. Even is the software existed it would require a big iron machine to be tied up for decades.
 2019-06-25, 08:08 #16 hansl     Apr 2019 5·41 Posts Well, yeah to put things in perspective it has ~6.77x as many bits as F33, which is still out of reach.
2019-06-25, 15:09   #17
ATH
Einyen

Dec 2003
Denmark

B5216 Posts

Quote:
 forprime(q=1,100000000000,s=Mod(1416317954,q);for(k=7,33,s=s^2-2;if(s==2,print([q,k-2]);break)))
Where did you get this algorithm from? Why do you think M58133053441 might be prime because S17 = 0 when S0 = 1416317954 ?

2019-06-25, 15:43   #18
Dr Sardonicus

Feb 2017
Nowhere

22·839 Posts

Quote:
 Originally Posted by paulunderwood forprime(q=1,100000000000,s=Mod(1416317954,q);for(k=7,33,s=s^2-2;if(s==2,print([q,k-2]);break)))
OK, I'll bite: Why does k begin at 7?

Code:
s=4;for(i=1,4,s=s^2-2;print(s))
14
194
37634
1416317954

2019-06-25, 16:24   #19
paulunderwood

Sep 2002
Database er0rr

32×7×53 Posts

Quote:
 Originally Posted by ATH Where did you get this algorithm from? Why do you think M58133053441 might be prime because S17 = 0 when S0 = 1416317954 ?
Because S21 = 0 when S0=4 and s+2 is a prime i.e 23 -- it works for M607:

Code:
p=607;s=Mod(4,p);for(k=1,3,s=s^2-2;print(s))
Mod(14, 607)
Mod(194, 607)
Mod(0, 607)
5 is prime!

It also works for say 8191, but that is the value of a Mersenne prime.

Last fiddled with by paulunderwood on 2019-06-25 at 16:25

2019-06-25, 16:29   #20
paulunderwood

Sep 2002
Database er0rr

333910 Posts

Quote:
 Originally Posted by Dr Sardonicus OK, I'll bite: Why does k begin at 7? Code: s=4;for(i=1,4,s=s^2-2;print(s)) 14 194 37634 1416317954
Normally we start at 3. Starting at 1416317954 saves a few iterations in a long program. I should have checked for s==0 instead that would have been quicker!

 2019-06-25, 16:57 #21 paulunderwood     Sep 2002 Database er0rr 64138 Posts Code: p=58133053441;e=lift(Mod(2,p^2-1)^p);Mod(Mod(1,p)*x,x^2-4*x+1)^(e) Mod(Mod(1, 58133053441), x^2 - 4*x + 1) But I cannot see how this helps.
 2019-06-25, 18:37 #22 paulunderwood     Sep 2002 Database er0rr 32×7×53 Posts Out of curiosity, how long would it take to test M665972737 on an average AVX2 desktop? Code: ? p=665972737;e=lift(Mod(2,p^2-1)^p)%p;Mod(Mod(1,p)*x,x^2-4*x+1)^(e) Mod(Mod(1, 665972737)*x, x^2 - 4*x + 1) Which seems quite remarkable. Additionally: Code: ? p=607;e=lift(Mod(2,p^2-1)^p)%p;lift(lift(Mod(Mod(1,p)*x,x^2-4*x+1)^(e))) 606*x + 4 ? p=60651732991;e=lift(Mod(2,p^2-1)^p)%p;lift(lift(Mod(Mod(1,p)*x,x^2-4*x+1)^(e))) 60651732990*x + 4 Last fiddled with by paulunderwood on 2019-06-25 at 19:18

 Similar Threads Thread Thread Starter Forum Replies Last Post a1call Miscellaneous Math 179 2015-11-12 14:59 Unregistered Information & Answers 7 2010-08-12 06:25 lfm Operation Billion Digits 6 2009-01-07 01:17 Shakaru Factoring 2 2005-02-23 19:22 Unregistered Software 3 2004-03-03 19:20

All times are UTC. The time now is 14:42.

Sat Aug 15 14:42:16 UTC 2020 up 2 days, 11:17, 1 user, load averages: 2.07, 1.81, 1.77