Fermat 12 factors already found?

[UberNumberGeek]

I have this in my results.txt:
[Tue Jun 16 13:45:22 2009]
ECM found a factor in curve #1, stage #1
Sigma=1258532066042594, B1=110000000, B2=11000000000.
UID: *******/OMFG, F12 has a factor: 36204694129087842739610650509313, AID: B70034B5180F2C7C2098F712D95D6584

But I also have this in my prime.log:
pnErrorDetail=Composite factor 36204694129087842739610650509313 = 114689 * 26017793 * 63766529 * 190274191361
Already have ECM factor 114689 for 2^4096+1
Already have ECM factor 26017793 for 2^4096+1
Already have ECM factor 63766529 for 2^4096+1
Already have ECM factor 190274191361 for 2^4096+1
CPU credit is 0.1039 GHz-days.

What's more, the result does not show up in my work results details and 4096 remains on http://v5www.mersenne.org/report_ECM/ .

Did I do something wrong when I manually added F12 to my worktodo? I used the ECM option under the Advanced menu of Prime95. I was initially extremely excited, but it looks like this isn't important at all. I didn't mean to waste cycles, my apologies; a least it only took an hour.

[UberNumberGeek]

Ditto for F13:
[Tue Jun 16 15:54:49 2009]
ECM found a factor in curve #1, stage #1
Sigma=2874099960753581, B1=110000000, B2=11000000000.
UID: *******/OMFG, F13 has a factor: 2710954639361, AID: 7175BCD346E9EFE192526B08C0CC4C3F

pnErrorDetail=Already have ECM factor 2710954639361 for 2^8192+1
CPU credit is 0.2125 GHz-days.

I am working on F14, F15, and F19. I fear getting the same results: already-known factors. I would very much appreciate knowing how I can amend my worktodo so as to prevent this from happening and to keep from wasting time duplication already-performed work. Thank you.

[TimSorbet]

I don't know too much about factoring with ECM through PrimeNet/Prime95, but you can find some known factors here:
http://factorization.ath.cx/search.php?query=Fx
For factoring Mersenne numbers, you can enter it here:
http://v5www.mersenne.org/report_factors/

[kar_bon]

the list of all Fermat factors is shown here: http://www.prothsearch.net/fermat.html

the current status of Fermat Search here: http://www.fermatsearch.org/stats/stats.php

[Prime95]

If you get an ECM Fermat assignment from the server it adds the known factors to the worktodo.txt line. These known factors are not reported.

If you've added the ECM line to worktodo.txt via the dialog box, then you'll need to add the list of known factors manually to the worktodo.txt line.

[UberNumberGeek]

Originally Posted by Mini-Geek

I don't know too much about factoring with ECM through PrimeNet/Prime95, but you can find some known factors here:
http://factorization.ath.cx/search.php?query=Fx
For factoring Mersenne numbers, you can enter it here:
http://v5www.mersenne.org/report_factors/

Thank you very much for the links! http://factorization.ath.cx/search.php?query=Fx is a very nice site. Forgive me, though, but http://v5www.mersenne.org/report_factors/ just lists found factors? Would I actually report any unknown finds through http://v5www.mersenne.org/manual_result/ ?

Originally Posted by kar_bon

the list of all Fermat factors is shown here: http://www.prothsearch.net/fermat.html


the current status of Fermat Search here: http://www.fermatsearch.org/stats/stats.php

Excellent sites! Yep, there are my factors. Well, still, maybe it's neat that the software was able to find those factors so quickly on only the first stage of the first curve? That's gotta be a stroke of good luck, yes?

Originally Posted by Prime95

If you get an ECM Fermat assignment from the server it adds the known factors to the worktodo.txt line. These known factors are not reported.

If you've added the ECM line to worktodo.txt via the dialog box, then you'll need to add the list of known factors manually to the worktodo.txt line.

Sir, thank you very much for providing me with this knowledge. Indeed, cannot thank you enough for ALL of this: the software, the math, the site, the immeasurable excitement which is growing all the more frequent. I found GIMPS in October of 1999, on my 22nd birthday, no less, and it's been a prominent fixture in my life ever since, just ask my wife and co-workers!

If I might trouble you with another question, where in the worktodo.txt line do I put the known factors? I tried to find the format in the readme and undoc files, and I asked for Fermat work but got F24 which has no known factors, yet.

My sincere thanks to you all.

[TimSorbet]

Originally Posted by UberNumberGeek

Thank you very much for the links! http://factorization.ath.cx/search.php?query=Fx is a very nice site. Forgive me, though, but http://v5www.mersenne.org/report_factors/ just lists found factors? Would I actually report any unknown finds through http://v5www.mersenne.org/manual_result/ ?

Yes, this is correct. Sorry for the ambiguity in my earlier statement. I meant that you could enter Mersenne exponents there and see known factors, not that you could enter a new factor for a Mersenne number there.

Originally Posted by UberNumberGeek

Excellent sites! Yep, there are my factors. Well, still, maybe it's neat that the software was able to find those factors so quickly on only the first stage of the first curve? That's gotta be a stroke of good luck, yes?

Considering the size of the B1 and B2 compared to the size of the factors, I'd say it's not unlikely at all. I don't know the math of how to figure the exact probability, but I know that B1/B2 sizes so large that it takes an hour for one stage of one curve is extreme overkill for 6-12 digit factors.

Originally Posted by UberNumberGeek

If I might trouble you with another question, where in the worktodo.txt line do I put the known factors? I tried to find the format in the readme and undoc files, and I asked for Fermat work but got F24 which has no known factors, yet.

I'm almost certain it's just like adding known_factors for PRP. Here's the excerpt for PRP from whatsnew.txt:

11) Program can now do PRP tests of (k*b^n+c)/f.  Add a line worktodo.txt that
    looks like this:
        PRP=k,b,n,c[,how_far_factored,tests_saved][,known_factors]
    The optional how_far_factored (in bits) and tests_saved values are used
    to determine if P-1 factoring prior to the PRP test would be beneficial.
    The optional known_factors list is a quoted comma separated list of
    known factors of k*b^n+c.

e.g. add

,"114689,26017793,63766529,190274191361,1256132134125569"

to the end of your ECM line.


It'd be nice if George or somebody could put together a few lists of all information about the Prime95 config files (what lines you can use, what options to give them, what the options do, what header(s) in what file(s) they go in, etc.). undoc.txt is closest to this, but isn't very clear on whether it goes in prime.txt or local.txt and what header(s) it is valid under. And, of course, it's lacking the worktodo.txt options (along with maybe some of the local.txt and prime.txt options, I'm not sure).
Once it's all put together, it could replace undoc.txt to be distributed with Prime95.