mersenneforum.org > Data Mersenne number factored (disbelievers are biting elbows)
 Register FAQ Search Today's Posts Mark Forums Read

 2019-04-06, 02:57 #452 Batalov     "Serge" Mar 2008 Phi(4,2^7658614+1)/2 3·3,229 Posts 2357 is a pretty prime number itself. (2, 3, 5, 7, you know) So it is doubly nice to have M2357 factored! Congrats, Ryan!
2019-04-06, 05:15   #453
axn

Jun 2003

23·229 Posts

Quote:
 Originally Posted by GP2 The cofactor will no doubt soon be certified prime on FactorDB.
Well, it is now...

2019-04-06, 07:38   #454
srow7

Jul 2014

648 Posts

something is wrong with the status of M2357.
F-ECM (factored)
P-PRP (probable prime) ?????
C-LL(verified)

Quote:
 https://www.mersenne.org/report_expo...exp_hi=&full=1 2019-04-05 ATH P-PRP M2357 is a probable prime. 2019-04-05 matzetoni P-PRP M2357/66747193058349253980250138299492944283449631375464079700189511 is a probable prime. 2019-04-05 Ryan Propper F-ECM Factor: 66747193058349253980250138299492944283449631375464079700189511

 2019-04-06, 08:59 #455 ATH Einyen     Dec 2003 Denmark 3,253 Posts I did use the factor in the worktodo line, so it is: M2357/66747193058349253980250138299492944283449631375464079700189511 that is PRP, but not sure why the history is wrong.
2019-04-06, 13:27   #456
Dr Sardonicus

Feb 2017
Nowhere

123448 Posts

Congrats on completing another factorization! Something on the factordb page piqued my curiosity:

Quote:
 Bases checked 5, 7, 11, 13, 125, 127
It seemed weird that 125 was selected as a base, seeing as how the base 5 was checked, and 125 = 5^3.

 2019-04-06, 13:54 #457 Batalov     "Serge" Mar 2008 Phi(4,2^7658614+1)/2 100101110101112 Posts FDB allows users to manually check in any base (one just types in the "base" and the server runs it). Running funny bases, like 91 or 35 is not a faux pas per se. But 125 _after_ 5, - yeah, that's a bit silly.
2019-04-06, 21:43   #458
Serpentine Vermin Jar

Jul 2014

22×3×277 Posts

Quote:
 Originally Posted by ATH I did use the factor in the worktodo line, so it is: M2357/66747193058349253980250138299492944283449631375464079700189511 that is PRP, but not sure why the history is wrong.
It's not wrong, it's just not displaying everything.

There is a frustrating amount of variations on how the JSON data was being formatted. Between the different builds of Prime95 and also gpuOwl, there was never really any agreement ahead of time on how it should look, so I've been playing catch-up with it.

For instance, the known factors may show up as a JSON array, or maybe as a value of comma separated numbers. Or maybe upper or lower case, or maybe it's another level deep, etc. LOL

George has settled on a (hopefully) final format in the latest builds of P95 but until we get the first example of something, I'm never really sure what it's going to look like.

Now that I see what a PRP looks like for a cofactor test, I can update the code that makes the raw result look pretty for the website. It did indeed change from:
Quote:
 "known-factors":"66747193058349253980250138299492944283449631375464079700189511"
to:
Quote:
 "known-factors":["66747193058349253980250138299492944283449631375464079700189511"]
Which is quite different. I had to go through the same thing with a non-prime result for cofactor PRP so it won't take me long to implement the new variation.

 2019-04-06, 23:56 #459 GP2     Sep 2003 5·11·47 Posts The 330th fully-factored or probably-fully-factored Mersenne number with prime exponent (not including the Mersenne primes themselves) is M78737. The 29-digit factor was found by Niels Mache Nextcloud, and the PRP test on Primenet was done by ATH. If certified prime, the cofactor would be a new record for Mersenne cofactors, beating the current M63703. However it would still be smaller than the Wagstaff prime with exponent 83339. Last fiddled with by GP2 on 2019-04-07 at 00:10
2019-04-08, 03:43   #460
petrw1
1976 Toyota Corona years forever!

"Wayne"
Nov 2006

137A16 Posts
Lightning strikes twice

Quote:
 Originally Posted by GP2 The 329th fully-factored or probably-fully-factored Mersenne number with prime exponent (not including the Mersenne primes themselves) is M2357. The 62-digit factor was found by Ryan Propper, and the PRP test on Primenet was done by matzetoni. The cofactor will no doubt soon be certified prime on FactorDB. This is a semiprime, and its exponent p = 1 mod 4.
2557 Factored 92006001376648044276967530077499930523710420381051263551
2019-04-07 Ryan Propper F-ECM
Factor: 92006001376648044276967530077499930523710420381051263551

2019-04-08, 04:28   #461
paulunderwood

Sep 2002
Database er0rr

23×173 Posts

Quote:
 Originally Posted by GP2 The 330th fully-factored or probably-fully-factored Mersenne number with prime exponent (not including the Mersenne primes themselves) is M78737. The 29-digit factor was found by Niels Mache Nextcloud, and the PRP test on Primenet was done by ATH. If certified prime, the cofactor would be a new record for Mersenne cofactors, beating the current M63703. However it would still be smaller than the Wagstaff prime with exponent 83339.
My test of Neils' find:

Code:
time ./pfgw64 -k -f0 -od -q"(2^78737-1)/23714605956035916529/67059801476528402969297162417" | ../../coding/gwnum/lucasPRP - 1 2 78737 -1

Lucas testing on x^2 - 3*x + 1 ...
Is Lucas PRP!

real	0m2.558s
user	0m2.200s
sys	0m0.008s

2019-04-08, 06:52   #462
Batalov

"Serge"
Mar 2008
Phi(4,2^7658614+1)/2

968710 Posts

Quote:
 Originally Posted by petrw1 2557 Factored 92006001376648044276967530077499930523710420381051263551 2019-04-07 Ryan Propper F-ECM
...but disbelievers (that it is fully factored) are not fools

 Similar Threads Thread Thread Starter Forum Replies Last Post preda PrimeNet 10 2018-11-04 00:47 c10ck3r Data 49 2017-12-10 19:39 Trejack FactorDB 7 2016-05-14 05:38 CRGreathouse Probability & Probabilistic Number Theory 15 2014-08-13 18:46 aketilander Operazione Doppi Mersennes 1 2012-11-09 21:16

All times are UTC. The time now is 17:39.

Thu Jan 20 17:39:16 UTC 2022 up 181 days, 12:08, 1 user, load averages: 1.99, 1.62, 1.52