Other primes thread

[nuggetprime]

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]

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

[gd_barnes]

Originally Posted by nuggetprime

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.

[nuggetprime]

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

Now 2nd largest GW.

--nuggetprime

[nuggetprime]

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

[gd_barnes]

Originally Posted by nuggetprime

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.

[em99010pepe]

5*2^2460482-1

[gd_barnes]

Originally Posted by em99010pepe

5*2^2460482-1

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]

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]

Originally Posted by gd_barnes

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

[mdettweiler]

Originally Posted by gd_barnes

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.