20090718, 15:12  #23  
Apr 2007
Spessart/Germany
166_{10} Posts 
Quote:
And yes, ECMF is slow (not to say boring), 7 curves with B1=250k at F23 needed 17 days with one core E6600@2400GHz. And as prime95 is able to work on Mersennenumbers with composite exponents, I recommen to add 2 more 'result types' (namely FECMF and NFECMF) to the result page of an account. Matthias 

20090718, 15:22  #24 
"Bo Chen"
Oct 2005
Wuhan,China
10110111_{2} Posts 

20090718, 15:32  #25 
P90 years forever!
Aug 2002
Yeehaw, FL
5·23·71 Posts 

20090718, 15:36  #26  
Apr 2007
Spessart/Germany
10100110_{2} Posts 
Quote:
Thank you! Matthias 

20090718, 15:57  #27  
Apr 2007
Spessart/Germany
2·83 Posts 
Quote:
But because prime95/mprime (the proggy used by the project GIMPS) offers a kind of work named 'ECM on Fermat numbers I think that my proposal makes sense for those, who are more interested in factoring M and Fnumbers (and other). And I think there are some user of this kind (like me ) Matthias 

20090718, 20:11  #28  
Dec 2008
179 Posts 
Quote:
Someone should probably report the new factor to http://www.prothsearch.net/fermat.html (unless they have and the page just haven't been updated yet). Last fiddled with by Random Poster on 20090718 at 20:16 

20090718, 20:14  #29 
Nov 2008
100100010010_{2} Posts 
According to the database, Markus (Syd) ran 5000 curves at B1=35e7. And that was on June 26. I suspect this is just complete nonsense added by the person claiming to be "Bill Gates".

20090719, 03:37  #30 
"Phil"
Sep 2002
Tracktown, U.S.A.
2^{5}·5·7 Posts 
Congratulations to everyone involved! This is quite a discovery, the tenth Fermat factor discovered by ECM, the first Fermat factor discovered by ECM since April 1999, and the largest Fermat number so far for which a factor has been found by ECM. As someone who has run many curves in the past, I can assure you that this discovery seemed overdue. A couple years ago, I estimated that the ECM effort since 1999 might have been expected to find an additional 4 factors, but the searched space just had not yielded a single one.
I notice that this factor seems to have shown up a bit late, in that the curves for the 35digit level had already been completed, with 2000 or so of the 4700 curves needed for the 40digit level also completed. What were the B2 bounds and the sigma of the discovery curve, George? Let's go find another one! 
20090719, 08:31  #31  
Banned
"Luigi"
Aug 2002
Team Italia
1001011111001_{2} Posts 
Quote:
Luigi 

20090719, 23:04  #32 
Jul 2009
Hobart, Australia
1011_{2} Posts 
Guess what I did this weekend.
I'm a physics major turned computer geek so a great deal of this thread is going over my head. Can anyone direct me to a good "Fermat Factoring 101" site so I can get a better grasp of this process.
David Bessell (no relation to Uncle Fredrick) 
20090720, 03:09  #33 
P90 years forever!
Aug 2002
Yeehaw, FL
5×23×71 Posts 
David Bessel from St Michael's Collegiate School in Australia is our Fermat factor discoverer  a.k.a. Buckle. Here is the results.txt output:
ECM found a factor in curve #3, stage #2 Sigma=7121198363696307, B1=3000000, B2=300000000. UID: Buckle/G810, F19 has a factor: 37590055514133754286524446080499713 
Thread Tools  
Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
GIMPS' second Fermat factor!  rajula  Factoring  103  20190312 04:02 
New Fermat factor found!  ET_  Factoring  5  20110113 11:40 
New Fermat factor!  ET_  Factoring  21  20100315 21:02 
New Fermat factor!  ET_  Factoring  42  20081201 12:50 
New Fermat factor found!  ET_  Factoring  3  20041214 07:23 