mersenneforum.org  

Go Back   mersenneforum.org > Factoring Projects > Factoring

Reply
 
Thread Tools
Old 2011-05-23, 09:17   #1
Syd
 
Syd's Avatar
 
Sep 2008
Krefeld, Germany

2·5·23 Posts
Default P-1 limits for Fermat numbers

Does anyone know how far the fermat numbers, say F12 to F30, have been tested using P-1-method?
I could only find some really old bounds.
Syd is offline   Reply With Quote
Old 2011-05-23, 10:05   #2
lorgix
 
lorgix's Avatar
 
Sep 2010
Scandinavia

10011001112 Posts
Default

http://www.prothsearch.net/fermat.html gives some info. You want the bottom of the page.
lorgix is offline   Reply With Quote
Old 2011-05-23, 10:59   #3
Syd
 
Syd's Avatar
 
Sep 2008
Krefeld, Germany

2·5·23 Posts
Default

Quote:
Originally Posted by lorgix View Post
http://www.prothsearch.net/fermat.html gives some info. You want the bottom of the page.
I think these are only the k tested, not the P-1 bounds. Or am I missing something there?
Syd is offline   Reply With Quote
Old 2011-05-23, 11:13   #4
lorgix
 
lorgix's Avatar
 
Sep 2010
Scandinavia

3×5×41 Posts
Default

If I understand this correctly, k must be the largest factor of p-1 if p divides F. Since any factor of F is of the form k*2^n+1.
lorgix is offline   Reply With Quote
Reply



Similar Threads
Thread Thread Starter Forum Replies Last Post
ecm with Fermat numbers ET_ FermatSearch 1 2016-08-02 19:40
P-1/P+1 on Fermat numbers ATH Operazione Doppi Mersennes 2 2015-01-25 06:27
LLT numbers, linkd with Mersenne and Fermat numbers T.Rex Math 4 2005-05-07 08:25
Fermat Numbers devarajkandadai Math 8 2004-07-27 12:27
Factoring Fermat Numbers Axel Fox Software 14 2003-07-04 18:57

All times are UTC. The time now is 14:26.


Fri Jul 16 14:26:49 UTC 2021 up 49 days, 12:14, 2 users, load averages: 1.92, 1.86, 1.77

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.