[QUOTE=houding;383518]On this page

[URL]http://www.mersenne.ca/prp.php?show=3&min_exponent=1&max_exponent=10%2C000%2C000[/URL]

1093 is also up for PRP testing.[/QUOTE]
It is not up for PRP testing.

Of course, everyone can run yet another PRP test on a known [I]prime[/I], but it doesn't make it a meaningful exercise.

It is wasteful for those who are unfamiliar with the Cunningham project to go below "[URL="http://homes.cerias.purdue.edu/~ssw/cun/"]min_exponent=1300[/URL]" (or, with its extensions, below 2400).
Dario is correct that the PRP-5701 is trivially proven prime. For comparison, Wu has just [URL="http://primes.utm.edu/primes/page.php?id=118512"]recently proven[/URL] a Wagstaff prime as large as 25,000 decimal digits. An ECPP proof for any number up to, say, 10000 decimal digits is a rather trivial exercise in 2014.

My apologies.

I guess (maybe I should not guess:smile:) that there is more to than just putting a PRP line from that page in P95 and running it, and then getting an answer yes it is PRP or not, and then telling someone about it. My favorite RDS will probably agree :grin:

I have some homework to do if i want to know that is all about.

Adolf

[QUOTE=alpertron;383494]Another probable prime:

M19121 = 917809 * 415147656569 * 1531543915081 * 27784129616513881634842031 * PRP-5701

This probable prime is in the range of a primality test.[/QUOTE]

I'm running a primality test on that now using Primo. I will report the result, or that I've abandoned it, at some point. :smile: So far, I'm at 18565/18938 bits.

I ran the P-1 factorization method with B1=200K, B2=5M on the range 900000-990000 and B1=2M, B2=50M on the range 990000-1000000, for the Mersenne numbers that already have known factors (in previous months I'd ran P-1 with B1=10M, B2=500M on all Mersenne numbers without known factors).

After finding more than 600 new prime factors, I ran PRP on the cofactors, but no new PRP appeared.

I started P-1 with B1=300K, B2=10M on the composite Mersenne numbers with exponents in the range 800000-900000.

[QUOTE=Mini-Geek;383537]I'm running a primality test on that now using Primo. I will report the result, or that I've abandoned it, at some point. :smile: So far, I'm at 18565/18938 bits.[/QUOTE]

Done, submitted to [url]http://www.factordb.com/index.php?id=1100000000710088779[/url]

Stop the presses!!!

After finding more than 1700 new prime factors of Mersenne numbers in the range 700K - 1M using P-1 algorithm, I finally discovered a PRP:

M750,151 = 429934042631 * 7590093831289 * 397764574647511 * 8361437834787151 * 17383638888678527263 * PRP-225744

Nice find! I suppose Primo won't prove it prime for a while yet... :)

[B]Earth[/B], also known as [B]Sol 3[/B], was a giant supercomputer designed to prove the primality of this number. Designed by Deep Thought and built by the Magratheans, it was commonly mistaken for a planet, especially by the ape descendants who lived on it. It was situated far out in the uncharted backwaters of the unfashionable end of the Western Spiral Arm of the Galaxy.

Unfortunately, the Earth was destroyed by the Vogons five minutes before the program was to be completed.

[QUOTE=Batalov;384424][B]Earth[/B], also known as [B]Sol 3[/B], was a giant supercomputer designed to prove the primality of this number. Designed by Deep Thought and built by the Magratheans, it was commonly mistaken for a planet, especially by the ape descendants who lived on it. It was situated far out in the uncharted backwaters of the unfashionable end of the Western Spiral Arm of the Galaxy.

Unfortunately, the Earth was destroyed by the Vogons five minutes before the program was to be completed.[/QUOTE]

:tu: :tu:

Thanks for this.

There is something to be said for dumb luck.
[CODE]M3464473/604874508299177 is a probable prime! We4: E866B6FC,00000000
[/CODE]
Still need to do some (slow) independent check with PFGW. Ugh!

EDIT:- Anybody know how to make P95 use a different base to do the PRP test?

That's the first Mega-PRP cofactor of a Mersenne number known. Congratulations.