M4219 completely factored?

[Jens K Andersen]

Originally Posted by MatWur-S530113

M1168183/54763676838381762583 is a probable prime!

Congratulations on beating my record!
You can also try submitting to http://donovanjohnson.com/mersenne.html

[MatWur-S530113]

Originally Posted by ixfd64

Maybe you'll be lucky enough to find a Mersenne prime next!

It's a long way from a 350k-digit-PRP to a 14m-digit-prime .

Originally Posted by Jens K Andersen

Congratulations on beating my record!
You can also try submitting to http://donovanjohnson.com/mersenne.html

Thank you
Donavan Johnson's site seems only to have a copy of Lifchitz's site, I haven't seen an invitation to sent results directly to him.
But maybe you know, how often Henri & Renaud Lifchitz are updating their site? (Of course I'm impatient ^^)
And may I ask: do you looked for PRP's in a complete region of exponents for the M-numbers? If yes, could you tell me the region to prevent me from senseless tests? I would very appreciate this.

greetings
Matthias

[Jens K Andersen]

Originally Posted by MatWur-S530113

Donavan Johnson's site seems only to have a copy of Lifchitz's site, I haven't seen an invitation to sent results directly to him.
But maybe you know, how often Henri & Renaud Lifchitz are updating their site? (Of course I'm impatient ^^)
And may I ask: do you looked for PRP's in a complete region of exponents for the M-numbers? If yes, could you tell me the region to prevent me from senseless tests? I would very appreciate this.

I mailed this to Donovan Johnson in April 2009:

I found the following probable primes with PrimeForm/GW.
They are all listed in http://www.primenumbers.net/prptop/prptop.php

Mersenne cofactors
(2^684127-1)/23765203727,205933
(2^406583-1)/813167,122388
(2^271549-1)/238749682487,81734
(2^271211-1)/613961495159,81631
(2^221509-1)/292391881,66673

2^n-1 was tested for prime n = 173891 to 729991 with factors in 
results.pfk.split.aa.bz2 at http://www.garlic.com/~wedgingt/mersenne.html
downloaded Jan 9 2009
dated Sep 30 (2008) in http://www.garlic.com/~wedgingt/facpriks.txt

He updated his site after the mail. I don't know whether he still accepts submissions.
I have not made further Mersenne cofactor searches since then. If you want I can mail a copy of the used factors I downloaded Jan 9 2009.
I think the PRP Top is usually updated around once a week. It was updated today and includes your prp as #15. You mentioned #14 earlier but there is another new addition at #6:

	(2^1669219-2^834610+1)/5	502485	Borys Jaworski	01/2011

[MatWur-S530113]

Thank you for your reply.
I think Donovan Johnson will see the changes if he is still updating his site regular. At least he has a link to Lifchitz' site
#14<->#15 was litte mistake by myself. I thougt to have found a 361k-digit number while looking at the list, but my prp has 'only' ~351k digits ^^.
As I can see from your mail to DJ you have testet all exponents up to 730000. I make a notice, maybe I will expand the region I test to 730000<p<1200000. But I still have to run ~1500 exponents for 1100000<p<1200000, thus it will last some days.
Thanks for the factors but I think I don't need them as I am regular downloading Will Edgington's (and Richard Brent's) factor tables by myself. And for M-numbers with exponent>200000 the GIMPS database is more helpful to find the new factors.

greetings
Matthias