mersenneforum.org  

Go Back   mersenneforum.org > Prime Search Projects > Prime Gap Searches

Reply
 
Thread Tools
Old 2021-03-18, 23:29   #34
SethTro
 
SethTro's Avatar
 
"Seth"
Apr 2019

11116 Posts
Default

Quote:
Originally Posted by CraigLo View Post
Hi everyone. I've been doing some prime gap searches for a couple weeks. Yesterday I tried to submit


2724 28.1621 3808817329*83# + 8863


I got a message in the queue

(2724, '3808817329', 'end not prime')


Am I doing something wrong or does the code not support positive offsets?
Server code just doesn't support it yet (if you add "/1" after 83# it probably would).

Should be fixed now

Last fiddled with by SethTro on 2021-03-19 at 00:07
SethTro is offline   Reply With Quote
Old 2021-03-19, 08:47   #35
robert44444uk
 
robert44444uk's Avatar
 
Jun 2003
Oxford, UK

1,933 Posts
Default

Quote:
Originally Posted by CraigLo View Post
Hi everyone. I've been doing some prime gap searches for a couple weeks. Yesterday I tried to submit


2724 28.1621 3808817329*83# + 8863

Nice gap! It is really tough to find records <3000
robert44444uk is offline   Reply With Quote
Old 2021-03-20, 12:30   #36
mart_r
 
mart_r's Avatar
 
Dec 2008
you know...around...

65010 Posts
Default

Quote:
Originally Posted by CraigLo View Post
2724 28.1621 3808817329*83# + 8863
I recognize that search strategy.
You get about 10% higher merits in the range around p# + or - p² than in a random search.
Still not as efficient as the deficient primorials though, but perhaps useful for "small" gaps.


Edit:
Quote:
Originally Posted by SethTro View Post
Server code just doesn't support it yet (if you add "/1" after 83# it probably would).

Should be fixed now
Pierre Cami had a gap in the list with a positive offset, 44909*43037# + 188014 (gap=230478).
(I haven't yet figured out how to attain the complete list of the github data... some help here, maybe?)
There are also some gaps with expression 6^n + ... and 2^n + ..., are they still there?

Last fiddled with by mart_r on 2021-03-20 at 12:57
mart_r is offline   Reply With Quote
Old 2021-03-21, 08:28   #37
SethTro
 
SethTro's Avatar
 
"Seth"
Apr 2019

3×7×13 Posts
Default

Quote:
Originally Posted by mart_r View Post
I recognize that search strategy.
You get about 10% higher merits in the range around p# + or - p² than in a random search.
Still not as efficient as the deficient primorials though, but perhaps useful for "small" gaps.


Edit:


Pierre Cami had a gap in the list with a positive offset, 44909*43037# + 188014 (gap=230478).
(I haven't yet figured out how to attain the complete list of the github data... some help here, maybe?)
There are also some gaps with expression 6^n + ... and 2^n + ..., are they still there?
You can see the raw list (it's too large for github to display in the nice editor)

https://raw.githubusercontent.com/pr...er/allgaps.sql

The issue would only affect records submitted via my front-end. I see some records starting with "6^13004 + ..." from MJPC&JKA (141970, 142450, and 144170)

It looks like Pierre Cami's 230478 gap record was improved by M.Jansen in 2021 22123#/210 - 64882.
SethTro is offline   Reply With Quote
Old 2021-03-21, 09:24   #38
MJansen
 
Jan 2018

43 Posts
Default

I was a little surpised to have my name attached to these records, since I was only aware of primorial searches, I guess Pierre must have send these to Tom.

Kind regards
Michiel Jansen

Last fiddled with by MJansen on 2021-03-21 at 09:33
MJansen is offline   Reply With Quote
Old 2021-03-21, 20:06   #39
mart_r
 
mart_r's Avatar
 
Dec 2008
you know...around...

12128 Posts
Default

Quote:
Originally Posted by SethTro View Post
You can see the raw list (it's too large for github to display in the nice editor)

https://raw.githubusercontent.com/pr...er/allgaps.sql

Thanks a lot!
Though my tablet has problems downloading/viewing the list, my dinosaur PC with a direct cable connection to the web handles it nicely and fast.
mart_r is offline   Reply With Quote
Old 2021-04-01, 15:11   #40
Bobby Jacobs
 
Bobby Jacobs's Avatar
 
May 2018

3·71 Posts
Default

Good job on the records!
Bobby Jacobs is offline   Reply With Quote
Old 2021-04-01, 16:32   #41
CraigLo
 
Mar 2021

100102 Posts
Default

I found 3 pretty large merits that are just outside the top 100.

10470 33.7912 17497330955201*307#/30 -6066
10470 33.7896 17755704968891*307#/30 -7496
10470 33.7881 18011066308391*307#/30 -4196

There is a larger merit for 10470. Is there a record for largest merit that is not a record?
CraigLo is offline   Reply With Quote
Old 2021-04-01, 16:56   #42
CraigLo
 
Mar 2021

2×32 Posts
Default

Quote:
Originally Posted by mart_r View Post
I recognize that search strategy.
You get about 10% higher merits in the range around p# + or - p² than in a random search.
Still not as efficient as the deficient primorials though, but perhaps useful for "small" gaps.

I did a test with A*97#/30, A mod 30 = 1 and A*97#/1. Both were run over the same number of A values.
With 97#/30 I found 1459 merits > 25.
With 97#/1 I found 1057 merits > 25.

I was checking a larger region for the 97#/1 case so it took longer but if I only checked the most promising regions I could probably get performance to within a factor of 2-3.
CraigLo is offline   Reply With Quote
Old 2021-04-02, 15:44   #43
henryzz
Just call me Henry
 
henryzz's Avatar
 
"David"
Sep 2007
Cambridge (GMT/BST)

2×5×587 Posts
Default

Quote:
Originally Posted by CraigLo View Post
I found 3 pretty large merits that are just outside the top 100.

10470 33.7912 17497330955201*307#/30 -6066
10470 33.7896 17755704968891*307#/30 -7496
10470 33.7881 18011066308391*307#/30 -4196

There is a larger merit for 10470. Is there a record for largest merit that is not a record?
We only keep the smallest for each gap size. A version of https://primegap-list-project.github...gh-watermarks/ that also listed gaps that were second best could be quite fun though. I tend to target my searches based on this list trying to get gaps on it. A second-best list would mean more targets. Some of the existing records are quite hard to beat.
Speaking of which I have just submitted: 232194 29.501 6099881 * 7993#/505915410 -59322 to +172872 which pushes 5 gaps off the list(including one of my own).

Still missing two personal targets: a gap of 1M and a 30 merit gap
henryzz is offline   Reply With Quote
Old 2021-04-03, 00:12   #44
SethTro
 
SethTro's Avatar
 
"Seth"
Apr 2019

3·7·13 Posts
Default

Quote:
Originally Posted by CraigLo View Post
I found 3 pretty large merits that are just outside the top 100.

10470 33.7912 17497330955201*307#/30 -6066
10470 33.7896 17755704968891*307#/30 -7496
10470 33.7881 18011066308391*307#/30 -4196

There is a larger merit for 10470. Is there a record for largest merit that is not a record?
If it was every a record it ends up in the git log and you can find them, if isn't a record at the time of discovery I don't know of any record keeping (you can submit them to my website and they end up in some log file but that's likely to be deleted at somepoint)

The highest merit non record gap I could find was a merit 33.5 by Jacobsen edged out by GapCoin this year

9738 Jacobsen 2016 33.4953 7850579863*283#/30 - 5534
SethTro is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Prime counting function records D. B. Staple Computer Science & Computational Number Theory 50 2020-12-16 07:24
records for primes 3.14159 Information & Answers 8 2018-12-09 00:08
Records for complete factorisation Brian-E Math 25 2009-12-16 21:40
gmp-ecm records page question yqiang GMP-ECM 6 2007-05-18 12:23
Records in January wblipp ElevenSmooth 10 2004-03-22 01:26

All times are UTC. The time now is 00:40.

Tue May 11 00:40:47 UTC 2021 up 32 days, 19:21, 2 users, load averages: 2.39, 2.34, 2.18

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.