Go Back > Great Internet Mersenne Prime Search > Math > Number Theory Discussion Group

Thread Tools
Old 2021-01-01, 21:00   #1
bhelmes's Avatar
Mar 2016

32210 Posts
Default a p+1 factoring test for Mp ?

A peaceful and pleasent new year 2021,

Is a p+1 factoring test for Mp possible or not ?

You could use complex numbers and make a similar factoring test like p-1.

In the section math there is no description about it

and I see no argument why this should not be possible.

Thanks if you spend me some lines.

bhelmes is online now   Reply With Quote
Old 2021-01-01, 21:30   #2
Batalov's Avatar
Mar 2008

41×229 Posts

Using Mp and p+1 in one sentence has an unintended consequence that your brain initially assumes that "p" is the same.
You should have phrased you question that (assumed) you mean Williams's p+1 algorithm. Where "p" is actually "f", i.e. the factor to be found.

It is possible but will be comparable to ecm. f+1 has the same chances to be smooth as any other number of the same size.*
Except you can run many ecm curves, but only one p+1 "curve".
*compare: for Mersennes, f-1 contains p, and (f-1)/p has a significantly better chance of being smooth than any sibling of f.
Batalov is offline   Reply With Quote

Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
Trial factoring after P1 test Lorenzo Information & Answers 3 2019-08-07 14:38
Yet another new factoring algorithm\primality test:Digital Coding ?? tServo Miscellaneous Math 3 2014-04-10 18:52
Trial factoring/P-1 torture test? cmokruhl Software 2 2005-08-03 03:54
Hardware failure only detected on torture test or also when factoring/LL-testing...? Jasmin Hardware 10 2005-02-14 01:58
I've chosen primality test task, but info shows P-1 factoring! Why ? Unregistered Software 3 2004-02-23 16:45

All times are UTC. The time now is 18:30.

Fri Apr 16 18:30:08 UTC 2021 up 8 days, 13:11, 0 users, load averages: 1.82, 1.89, 2.26

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.