mersenneforum.org  

Go Back   mersenneforum.org > Prime Search Projects > No Prime Left Behind

Reply
 
Thread Tools
Old 2008-10-16, 14:53   #1
nuggetprime
 
nuggetprime's Avatar
 
Mar 2007
Austria

12E16 Posts
Default Other primes thread

I think I'm starting a thread like in RPS here for non-riesel primes found by NPLB members/special riesel primes found by others.

--nuggetprime
nuggetprime is offline   Reply With Quote
Old 2008-10-16, 14:56   #2
nuggetprime
 
nuggetprime's Avatar
 
Mar 2007
Austria

2·151 Posts
Default First prime

Found 6th largest Generalized Woodall Prime:
91850*19^91850-1 is prime!

This is one of only 3 top-5000 primes found by phil's phrot and the first bigger/top5000 discovery for Geoff's phrot port for linux.

--nuggetprime
nuggetprime is offline   Reply With Quote
Old 2008-10-16, 20:12   #3
gd_barnes
 
gd_barnes's Avatar
 
May 2007
Kansas; USA

100111011011102 Posts
Default

Quote:
Originally Posted by nuggetprime View Post
Found 6th largest Generalized Woodall Prime:
91850*19^91850-1 is prime!

This is one of only 3 top-5000 primes found by phil's phrot and the first bigger/top5000 discovery for Geoff's phrot port for linux.

--nuggetprime

Great idea nugget! VERY nice find! It's nice to see primes discovered in other bases.
gd_barnes is offline   Reply With Quote
Old 2008-10-25, 08:37   #4
nuggetprime
 
nuggetprime's Avatar
 
Mar 2007
Austria

30210 Posts
Default

Nearly breaking Kosmaj's GW record:
146478*19^146478-1 is prime!(187315 digits)

Now 2nd largest GW.

--nuggetprime
nuggetprime is offline   Reply With Quote
Old 2008-11-07, 17:26   #5
nuggetprime
 
nuggetprime's Avatar
 
Mar 2007
Austria

2·151 Posts
Default The new world record

As you may have already noticed, a few days ago I found the largest known GW prime:
189620*19^189620-1 is prime!(242483 digits)

--nuggetprime

Last fiddled with by nuggetprime on 2008-11-07 at 17:26
nuggetprime is offline   Reply With Quote
Old 2008-11-08, 09:07   #6
gd_barnes
 
gd_barnes's Avatar
 
May 2007
Kansas; USA

2·72·103 Posts
Default

Quote:
Originally Posted by nuggetprime View Post
As you may have already noticed, a few days ago I found the largest known GW prime:
189620*19^189620-1 is prime!(242483 digits)

--nuggetprime

Tremendous nugget! Way to go! Top of the heap now.
gd_barnes is offline   Reply With Quote
Old 2008-11-19, 13:26   #7
em99010pepe
 
em99010pepe's Avatar
 
Sep 2004

2×5×283 Posts
Default

5*2^2460482-1
em99010pepe is offline   Reply With Quote
Old 2008-11-19, 14:53   #8
gd_barnes
 
gd_barnes's Avatar
 
May 2007
Kansas; USA

2×72×103 Posts
Default

Quote:
Originally Posted by em99010pepe View Post

So THAT is where Benson has been at all this time!

I guess for a score of 423, it was worth it. That equals about 100 of our n=550K primes! :surprised

It will move him up to #17 on the scores list at top-5000. If you remove the people who have found < 5 primes, he'd be #3!

Benson, can you help push our 1st drive a little? lol


Gary
gd_barnes is offline   Reply With Quote
Old 2009-01-20, 00:58   #9
gd_barnes
 
gd_barnes's Avatar
 
May 2007
Kansas; USA

235568 Posts
Default

Something smells extremely fishy about this recent huge submission:

http://primes.utm.edu/primes/page.php?id=86270

First time searcher...huge prime...at or near power-of-10 k and n-value...I've seen this kind of thing before and I'm thinking not! It looks like a "wannabe" prime. But who knows? Stranger things have happened!

I'm putting a slow sore on sieving it to at least P=10G to see if I can save the top-5000 site a little time. I know they do trial factoring before primality testing but I don't know if they sieve. I ran srsieve to P=300M with no factors found and now have it on sr1sieve, which appears will take ~5-10 mins. to build a Legendre symbol table before starting a much faster sieve.

If it turns out to be prime, I'll be the first to retract my first para. here.


Gary
gd_barnes is offline   Reply With Quote
Old 2009-01-21, 05:20   #10
gd_barnes
 
gd_barnes's Avatar
 
May 2007
Kansas; USA

2×72×103 Posts
Default

Quote:
Originally Posted by gd_barnes View Post
Something smells extremely fishy about this recent huge submission:

http://primes.utm.edu/primes/page.php?id=86270

First time searcher...huge prime...at or near power-of-10 k and n-value...I've seen this kind of thing before and I'm thinking not! It looks like a "wannabe" prime. But who knows? Stranger things have happened!

I'm putting a slow sore on sieving it to at least P=10G to see if I can save the top-5000 site a little time. I know they do trial factoring before primality testing but I don't know if they sieve. I ran srsieve to P=300M with no factors found and now have it on sr1sieve, which appears will take ~5-10 mins. to build a Legendre symbol table before starting a much faster sieve.

If it turns out to be prime, I'll be the first to retract my first para. here.


Gary

I ended up sieving 100000005*2^10000000-1 to P=25G...no factors found.

I just now saw that the submission was proven composite...no surprise there. See http://primes.utm.edu/primes/page.php?id=86270. Also, another "smaller" submission for 1767766^32768+1 by the same person at http://primes.utm.edu/primes/page.php?id=86278 was also proven composite.

It's clear that he did some sieving and then submitted them without primality testing hoping that they were prime. In doing that, he wasted over a day worth of CPU time at the top-5000 site causing the proof of all of our legitimate submissions to slow down greatly. (I observed this.)

Mr. Musatov, you are a bane to the prime-searching community! Put in the CPU time like everyone else!


Gary

Last fiddled with by gd_barnes on 2009-01-21 at 05:22
gd_barnes is offline   Reply With Quote
Old 2009-01-21, 15:15   #11
mdettweiler
A Sunny Moo
 
mdettweiler's Avatar
 
Aug 2007
USA (GMT-5)

3·2,083 Posts
Default

Quote:
Originally Posted by gd_barnes View Post
I ended up sieving 100000005*2^10000000-1 to P=25G...no factors found.

I just now saw that the submission was proven composite...no surprise there. See http://primes.utm.edu/primes/page.php?id=86270. Also, another "smaller" submission for 1767766^32768+1 by the same person at http://primes.utm.edu/primes/page.php?id=86278 was also proven composite.

It's clear that he did some sieving and then submitted them without primality testing hoping that they were prime. In doing that, he wasted over a day worth of CPU time at the top-5000 site causing the proof of all of our legitimate submissions to slow down greatly. (I observed this.)

Mr. Musatov, you are a bane to the prime-searching community! Put in the CPU time like everyone else!


Gary
I think users will get banned at the top-5000 site if they submit too many composite primes. Not sure exactly how many's the limit though.
mdettweiler is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Mersenne Primes p which are in a set of twin primes is finite? carpetpool Miscellaneous Math 3 2017-08-10 13:47
Distribution of Mersenne primes before and after couples of primes found emily Math 34 2017-07-16 18:44
Thread for posting tiny primes 3.14159 Miscellaneous Math 945 2015-07-26 21:43
possible primes (real primes & poss.prime products) troels munkner Miscellaneous Math 4 2006-06-02 08:35
Deutscher Thread (german thread) TauCeti NFSNET Discussion 0 2003-12-11 22:12

All times are UTC. The time now is 22:13.

Sat Apr 4 22:13:24 UTC 2020 up 10 days, 19:46, 0 users, load averages: 1.92, 1.61, 1.55

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, 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.