Mersenne number factored (disbelievers are biting elbows) - Page 51

GP2 · 2021-03-20, 19:52

The 351st fully-factored or probably-fully-factored Mersenne number with prime exponent (not including the Mersenne primes themselves) is M8233.

The most recent factor (47 digits) was found by Bruno Victal on 2021-03-20 and the PRP test was done by user "mikr".

FactorDB link

Dr Sardonicus · 2021-03-21, 01:01

Quote:

Originally Posted by GP2

The 351st fully-factored or probably-fully-factored Mersenne number with prime exponent (not including the Mersenne primes themselves) is M8233

Pardon my ignorance, but what is the "type" of a PRP test? I can't remember the last time I saw an exponent status page in which the type of a PRP test was anything but 1. I noticed that this one had a PRP test of "type" 5 rather than 1.

kriesel · 2021-03-21, 02:20

Quote:

Originally Posted by Dr Sardonicus

what is the "type" of a PRP test? I can't remember the last time I saw an exponent status page in which the type of a PRP test was anything but 1. I noticed that this one had a PRP test of "type" 5 rather than 1.

From the undoc.txt of prime95 zip file:

Code:

PRP supports 5 types of residues for compatibility with other PRP programs.  If
a is the PRP base and N is the number being tested, then the residue types are:
1 = 64-bit residue of a^(N-1), a traditional Fermat PRP test used by most other programs
2 = 64-bit residue of a^((N-1)/2)
3 = 64-bit residue of a^(N+1), only available if b=2
4 = 64-bit residue of a^((N+1)/2), only available if b=2
5 = 64-bit residue of a^(N*known_factors-1), same as type 1 if there are no known factors

Gpuowl has implemented type 1 mostly, type 4 in some versions. In gpuowl V5.0, simultaneous P-1 and PRP was implemented IIRC as a "type 0" using a large base related to P-1 B1, IIRC.
https://www.mersenneforum.org/showpo...32&postcount=8
https://mersenneforum.org/showpost.p...postcount=1255
https://www.mersenneforum.org/showpo...3&postcount=15

I think Mlucas does type 1.

Type 1 is standard for PRP primality test of no-known-factor Mersenne numbers. Type 5 is standard for PRP-CF.

LaurV · 2021-03-21, 13:49

Quote:

Originally Posted by GP2

The 351st fully-factored or probably-fully-factored Mersenne number with prime exponent (not including the Mersenne primes themselves) is M8233.

The most recent factor (47 digits) was found by Bruno Victal on 2021-03-20 and the PRP test was done by user "mikr".

FactorDB link

I've seen this one as I got it immediately assigned for DC

(still in queue, it will be done tomorrow or the day after).
I could move it to the front, but as I have no doubt that is PRP, let it be.
Congrats to the finder(s) !

kruoli · 2021-03-22, 14:10

Quote:

Originally Posted by GP2

The 351st fully-factored or probably-fully-factored Mersenne number with prime exponent (not including the Mersenne primes themselves) is M8233.

The cofactor is now certified prime: http://factordb.com/index.php?id=1100000002528023613.

GP2 · 2021-03-26, 06:28

The 352nd fully-factored or probably-fully-factored Mersenne number with prime exponent (not including the Mersenne primes themselves) is M7669.

The most recent factor (47 digits) was found by Ryan Propper on 2021-03-26 and the PRP test was done by user "mikr".

FactorDB link

The cofactor is already certified prime.

GP2 · 2021-03-27, 14:46

The 353rd fully-factored or probably-fully-factored Mersenne number with prime exponent (not including the Mersenne primes themselves) is M7013.

The most recent factor (49 digits) was found by Ryan Propper on 2021-03-27 and the PRP test was done by user "riccardo uberti".

FactorDB link

The cofactor is already certified prime.

axn · 2021-03-27, 16:02

That's 3 in a week. Noice!

GP2 · 2021-04-07, 16:33

The 354th fully-factored or probably-fully-factored Mersenne number with prime exponent (not including the Mersenne primes themselves) is M5393.

The most recent factor (58 digits) was found by Ryan Propper on 2021-04-07 and the PRP test was done by user "mnd9". Ryan also found a 54-digit factor last October. The only other factor has 5 digits (32359).

FactorDB link

The cofactor is already certified prime.

GP2 · 2021-04-18, 16:22

There are now 355 known Mersenne numbers with prime exponent that are composite and either fully factored or probably fully factored.

The most recent is M4507. Its final factor (53 digits) was found by Ryan Propper on 2021-04-18 and the PRP test was done by user "ThomRuley".

FactorDB link

The cofactor is already certified prime.

ATH · 2021-04-28, 23:27

Ryan Propper found another factor and another PRP #356: M3917

2021-03-20, 19:52	#551
GP2 Sep 2003 3·863 Posts	The 351st fully-factored or probably-fully-factored Mersenne number with prime exponent (not including the Mersenne primes themselves) is M8233. The most recent factor (47 digits) was found by Bruno Victal on 2021-03-20 and the PRP test was done by user "mikr". FactorDB link Last fiddled with by GP2 on 2021-03-20 at 19:54

2021-03-27, 14:46	#557
GP2 Sep 2003 3×863 Posts	The 353rd fully-factored or probably-fully-factored Mersenne number with prime exponent (not including the Mersenne primes themselves) is M7013. The most recent factor (49 digits) was found by Ryan Propper on 2021-03-27 and the PRP test was done by user "riccardo uberti". FactorDB link The cofactor is already certified prime. Last fiddled with by GP2 on 2021-03-27 at 14:46

2021-04-28, 23:27	#561
ATH Einyen Dec 2003 Denmark 19×181 Posts	Ryan Propper found another factor and another PRP #356: M3917 Last fiddled with by ATH on 2021-04-28 at 23:29

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2021-03-26, 06:28	#556
GP2 Sep 2003 3·863 Posts	The 352nd fully-factored or probably-fully-factored Mersenne number with prime exponent (not including the Mersenne primes themselves) is M7669. The most recent factor (47 digits) was found by Ryan Propper on 2021-03-26 and the PRP test was done by user "mikr". FactorDB link The cofactor is already certified prime.

2021-03-27, 16:02	#558
axn Jun 2003 153E₁₆ Posts	That's 3 in a week. Noice!

2021-04-07, 16:33	#559
GP2 Sep 2003 3×863 Posts	The 354th fully-factored or probably-fully-factored Mersenne number with prime exponent (not including the Mersenne primes themselves) is M5393. The most recent factor (58 digits) was found by Ryan Propper on 2021-04-07 and the PRP test was done by user "mnd9". Ryan also found a 54-digit factor last October. The only other factor has 5 digits (32359). FactorDB link The cofactor is already certified prime.

2021-04-18, 16:22	#560
GP2 Sep 2003 A1D₁₆ Posts	There are now 355 known Mersenne numbers with prime exponent that are composite and either fully factored or probably fully factored. The most recent is M4507. Its final factor (53 digits) was found by Ryan Propper on 2021-04-18 and the PRP test was done by user "ThomRuley". FactorDB link The cofactor is already certified prime.