Congrats to Bishop (L3514) and Primegrid on new largest Fermat divisor:

57*2^2747499+1 (827082 digits)

As a reminder, a prime of form k*2^n+1 can be Fermat divisor with probability 1/k regardless of n.

BTW, the legendary record Fermat divisor found by Cosgrave in 2003 (3*2^2478785+1) is now 3rd!

[QUOTE=Kosmaj;340532]Congrats to Bishop (L3514) and Primegrid on new largest Fermat divisor:

57*2^2747499+1 (827082 digits)

As a reminder, a prime of form k*2^n+1 can be Fermat divisor with probability 1/k regardless of n.

BTW, the legendary record Fermat divisor found by Cosgrave in 2003 (3*2^2478785+1) is now 3rd![/QUOTE]


This is not listed on [url]www.prothsearch.net/fermat.html[/url] yet.
Such results surprise me, since I expect that simple multiplication of 2 numbers of this size should last years. There must be technique I am not aware of.
It is not written what Fermat number has this divisor, but for sure we even cannot imagine the size of this Fermat number.

Congrats to Batalov on nice primes based on known Mersenne primes:

507568*(2^1398269-1)+1, 420927 digits
374568*(2^3021377-1)+1, 909531 digits

BTW, there seems to be a way to include the helper with your submission,
so that the verification on CC's server is done using the helper. See here:
[url]http://primes.utm.edu/primes/page.php?id=115087[/url]

Well, [URL="http://primes.utm.edu/primes/page.php?id=115540"]here's a prime[/URL] that is easy to write down.
It is a "one", followed by 1,059,002 "nines".

Full size posters are available from primes'Я'us.ru ;-)

Congratulations!!!!

There's a large Riesel Problem prime in verification.
It will come in [URL="http://primes.utm.edu/primes/page.php?id=115858"]in position #23[/URL]. Congrats to PGrid!

And a day later, [URL="http://primes.utm.edu/primes/page.php?id=115875"]one more[/URL], also in position #23. ;-)

Yeah, one more:
[URL="http://primes.utm.edu/primes/page.php?id=115875"]304207*2^6643565-1[/URL] (1999918 digits)

Only 82 digits shy of 2M digits!
That's that guy Randy who joined prime search in June this year and already has more than 500 primes in Top-5000, is first by number, and with this one will probably become 11th by score. Amazing computing power! :shock:

Batalov found [url]http://primes.utm.edu/primes/page.php?id=116472[/url]. Congratulations!

Yeah, indeed congrats to Batalov.

And a great chance for the new Fermat divisor record!

[url]http://primes.utm.edu/primes/page.php?id=116744[/url]

A huge [URL="http://primes.utm.edu/primes/page.php?id=116922"]Proth prime[/URL] was found by Tang&PrimeGrid.
I wonder if they are [I]still[/I] in the process of running the xGF tests.

(They should have parallelized them into a lot of "foreach i (2 3 5 6 10 12) pfgw -gos$i -lgos$i.log p" processes. For a plainly run "pfgw -gxo p" result, they may wait for days/weeks. It is also possible to write a parallel implementation, based on the PRP test in Prime95: just a few lines need to be changed and then a GF-divisor test could have been be run threaded, i.e. much faster still.)