Go Back > Prime Search Projects > No Prime Left Behind

Thread Tools
Old 2008-02-11, 19:23   #1
gd_barnes's Avatar
May 2007
Kansas; USA

52×421 Posts
Default Here's why we double-check...

Here is an excellent example of why we double check:

To the best of our knowledge, high-weight k=945 had been previously searched up to n=260K as of 8/15/04. An error had already been found in our double-check up to n=100K. A prime reported at n=21062 is actually n=31062. This was corrected many months ago on Karsten's pages. We are still working with Michael Hartley on some corrections for Prime Search.

Subsequent to this, a prime was reported to the top-5000 site at n=350126 on 10/6/07 thru the old 15K project, which apparently is still running in some form.

The above might lead one to assume that the k had been searched contiguously past n>350K. That would be a poor assumption. NPLB has already found TWO top-5000 primes for n<350K!!:

945*2^342774-1 found by Chris (Flatlander) on 2/3
945*2^349086-1 found by me today (2/11)

Clearly someone either started their testing at n=350K or possibly did a fixed-n search and in doing so missed 2 out of 3 primes of a very nice run in a range of n<7500.

So there you have it...


Last fiddled with by gd_barnes on 2008-02-11 at 19:29
gd_barnes is offline   Reply With Quote

Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
Double-Check wombatman Conjectures 'R Us 3 2016-08-29 20:46
Double Check Unregistered Information & Answers 3 2011-10-01 04:38
First check and double check llrnet servers. opyrt Prime Sierpinski Project 3 2009-01-02 01:50
Double-check check? M0CZY Software 15 2008-10-30 14:20
Double Check P-1 PhilF PrimeNet 6 2005-07-03 14:36

All times are UTC. The time now is 22:31.

Tue Oct 26 22:31:16 UTC 2021 up 95 days, 17 hrs, 1 user, load averages: 1.29, 1.17, 1.19

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.