[QUOTE=Gordon;435373]Here we go again :bangheadonwall:

This number is NOT fully factored, it is suspected fully factored.

the P stands for PROBABLE not DEFINITELY[/QUOTE]

To contribute actual information to this thread, perhaps you could tell us what the chances are this number is not fully factored?
Nobody who has posted thus far in the thread was confused about what "prp" stands for, so you haven't contributed anything yet, despite your "here we go again, I must educate you idiots" tone.

(2^4187251-1)/72234342371519 is Lucas PRP! (303222.4932s+0.0828s)

[QUOTE=ATH;435626](2^4187251-1)/72234342371519 is Lucas PRP! (303222.4932s+0.0828s)[/QUOTE]

Is that with a dedicated intel AVX core?

Compare it to [URL="http://www.mersenneforum.org/showpost.php?p=435426&postcount=33"]my 3 hour test[/URL] which does (Fermat+)Lucas albeit threaded on 4 cores at ~57% efficiency.

No it was 1 core competing with Prime95. But I was using PFGW which is running a lot of N+1 test stuff I believe before it actually starts doing a Lucas PRP test. I wish someone could figure out how to start the PFGW lucas test directly without anything before it (see the pfgw thread).

I did not know you did a Lucas test, your post does not mention a Lucas test. I thought you were running your own test. Do you have an FFT Lucas test? I only have a GMP version which would have taken even longer than PFGW I'm sure.

It would be relatively easy for some one to [URL="http://www.mersenneforum.org/showpost.php?p=409907&postcount=9"]hack my code[/URL]. As for the jacobi symbol, I usually use pari/GP, but it would be possible to code something using "giants". If no one steps up to the plate, I will do it without giving a deadline :wink:

[QUOTE=ATH;435626]... PRP...[/QUOTE]:tu: [color=#F5F5FF][Gordon]Oh, so it's not prime then.[/Gordon][/color]

[QUOTE=paulunderwood;435631]It would be relatively easy for some one to [URL="http://www.mersenneforum.org/showpost.php?p=409907&postcount=9"]hack my code[/URL]. As for the jacobi symbol, I usually use pari/GP, but it would be possible to code something using "giants". If no one steps up to the plate, I will do it without giving a deadline :wink:[/QUOTE]

You could easily find it with a few lines of GMP code in the beginning:

[QUOTE]int mpz_jacobi (const mpz t a, const mpz t b)
Calculate the Jacobi symbola b
. This is defined only for b odd.[/QUOTE]

[QUOTE=ATH;435644]You could easily find it with a few lines of GMP code in the beginning:[/QUOTE]

Thanks for the tip. I have written using giants for now (and it is clunky at the beginning) but I am getting 374% CPU usage on 4 cores with gwnum. Expect a (good) result soon :smile:

[code]time ~/coding/gwnum/lucasPRP M4187251-cofactor 1 2 4187251 -1
Lucas testing on x^2 - 3*x + 1 ...
Is Lucas PRP!

real 67m17.818s
user 241m28.104s
sys 7m14.548s
[/code]

[URL="http://www.mersenneforum.org/showpost.php?p=435654&postcount=12"]reference program[/URL]

M5240707 PRP
 

I'm not sure when this happened, but mersenne.ca is showing a new highest probable prime:

2^5240707-1 = 75392810903 * PRP-1577600

[CODE] time ~/coding/gwnum/lucasPRP M5240707-cofactor 1 2 5240707 -1
Lucas testing on x^2 - 4*x + 1 ...
Is Lucas PRP!

real 80m1.965s
user 292m51.600s
sys 4m42.136s
[/CODE]

Now running a different test ... :smile: