fond of a factor? Urn yourself to become remains

[aketilander]

Originally Posted by Batalov

(easy warm-up) M1091 has a prime factor 2·k·1091+1

M10169 has a prime factor 2·k·10169+1

Question: Is it the largest factors of M1091 and M10169 which you have proved being prime?

[firejuggler]

for M1091, yup this is the largest factor and for 10169 has only 2 factor, a P41 and a PRP3022

[ET_]

Originally Posted by firejuggler

for M1091, yup this is the largest factor and for 10169 has only 2 factor, a P41 and a PRP3022

Anybody started a certification with primo on it?

Luigi

[Batalov]

M10169: I've factored k yesterday (arguably not hard, and probably had been done before, but it wasn't in the FactorDB anyway) and left a certification on an old primo3.0.9. It is really slow.
For the fun of it, I've started a 4-thread certification with primo4.0a14 and it will probably take only a couple hours. I'll d/l it.

(EDIT: DB is going to immediately certify the cofactor obviously, as soon as prp2988 cert is d/l-ed.)

(EDIT2: M10169 FF wasn't new - search the forum; I took a few fully factored Mp with p>10,000 and ran a few curves on their k values for the largest factor - just to instigate a conversation)

[markr]

P-1 found a factor in stage #2, B1=505000, B2=9595000.
M52182167 has a factor: 2029482487582610831696273
k = 2^3 x 1049 x 242677 x 9548587
9548587 / 9595000 = 0.9952...

[alpertron]

I found another large prime factor of a Mersenne number. Its length is 130 bits.

P-1 found a factor in stage #1, B1=10000000.
M799417 has a factor: 737227711675437329857373483171104386487

k = 3² × 61 × 619 × 14207 × 202387 × 580687 × 791663 × 1026521

[TObject]

M344111197 has a factor: 462638685260988598273
k = 2^10 * 3 * 218822479 = 672222655488

[c10ck3r]

Anybody interested in my list of 1041 factors found thus far? I can sort for certain ranges of exponents if needed... shoot me a PM with your email and which ranges you are interested in. Thanks!

[Stef42]

M746199263 has a factor: 91476779052406004953 [TF:65:66:mfaktc 0.18 barrett79_mul32]
M746199263 has a factor: 88811032749292964359 [TF:65:66:mfaktc 0.18 barrett79_mul32]
found 2 factors for M746199263 from 2^65 to 2^66 [mfaktc 0.18 barrett79_mul32]

Stats link.

k = 3⁴ × 734678093

k = 2² × 3 × 191 × 26743081

[flashjh]

Found a nice K:

M58453471
Factor: 3893338465413479482783
Digits: 22
Bits: 71.722
K = 3 × 11100961724507

[markr]

M54676967 has a factor: 420411039467695302913223737
89 bits, but so smooth*
2^2 × 3 × 7 × 167 × 293 × 569 × 593 × 1327 × 2089

* I'd cue davieddy but he might choose Mancini over Santana.