[QUOTE=jnml;331225]M9551624981928189737<snip> has a factor: 19103249963856379475<snip>[/QUOTE]... and the cofactor is ?

not prime, with a 99.9% chance.

[QUOTE=cheesehead;331602]... and the cofactor is ?[/QUOTE]
I think the cofactor is non computable (in this case).

[code][Sat Mar 2 00:40:06 2013]
P-1 found a factor in stage #1, B1=585000.
UID: daran/agogo, M61797677 has a factor: 14080954256065607739793951951487, AID: F930BE0F01061A1D5C0134A93FA87741[/code]

At 104 bits this is my largest stage 1 factor ever. k = 41 * 409 * 15683 * 25309 * 36919 * 463627.

P-1 found a factor in stage #1, B1=575000.
M60808259 has a factor: 592791747603566405334727072882584265279
128.80 Bits; k = 4874270019830418145458884728821 = 3 * 22013 * 25219 * 41999 * 391133 * 407311 * 437413
A little bit above the average size of my stage 1 results. :smile:

Oliver

Got an 88 bit hit some days ago. :smile:

[url]http://www.mersenne.ca/exponent.php?exponentdetails=61557059[/url]

I just [URL="https://www.gpu72.com/reports/worker/factors/d0a0a9610115a8227c686f0d8951998b/bydate/"]got[/URL] a 77 bit factor for (M)60181483. Boohoo. :evil:

[SIZE="1"](finding about roughly 1 P-1 factor a day)[/SIZE]

Y'know how P-1 finds factors that would take ages to find using TF? Well, does anyone have some good examples where TF would be similarly many times faster than P-1?

[QUOTE=c10ck3r;333695]Y'know how P-1 finds factors that would take ages to find using TF? Well, does anyone have some good examples where TF would be similarly many times faster than P-1?[/QUOTE]
Something with a 39- or 40-bit prime k (for the range of typical exponents now being tested) would do it, I think.

I guess, actually any k with a largest prime factor over 25 bits, which would require P-1 B2 > 30M, and a second-largest prime factor large enough to require a high B1. Something like that.

Someone could work out a more specific function depending on size of exponent and sizes of largest two prime factors of k, and post some nice curves on a graph.

(Maybe if I get energetic like when I was younger, and have spare time. Or if I'd ever become a Mathematica master like I once intended. With that 3-D display floating in the air like I dreamed up in high school calculus class, plus hand-gesture controls.

Heh.)

That's easy. For example:

Factor 8643081839402111473 (63 bits) of M60004193 would require a B2 of 142898113
Factor 6104384570413241087 (63 bits) of M60005497 would require a B2 of 3912708563
Factor 630004667994632017847 (70 bits) of M60000049 would require a B2 of 477275873857

Okay, quick question: if, for example, a prime k-value is between B1 and B2, will it be found by stage 2? For example, M1277 shows a B1 of 2*10^12 and a B2 of 3*10^13. If there was a prime k-value of about, say, 1*10^13, would stage 2 find it?
If so, does this mean it has, through P-1, been effectively TF'ed to 96.95 bits? (2*1277*2e12*3e13)