20110324, 12:24  #12 
"Nancy"
Aug 2002
Alexandria
4643_{8} Posts 
If you want multiplications modulo Fermat numbers, you should call the SchönhageStrassen code in GMP directly (mul_fft) since it has an implicit modulus 2^n+1. That should give you a factor 2 speedup and asymptotically O(n log(n) log(log(n))) runtime.

20110623, 10:31  #13 
"Mark"
Apr 2003
Between here and the
2^{3}×739 Posts 
9*2^2543551+1 Divides F2543548, found by PrimeGrid.

20110623, 21:44  #14 
"Mark"
Apr 2003
Between here and the
2^{3}·739 Posts 
7333*2^138560+1 Divides F(138557), also by PrimeGrid

20110702, 23:58  #15 
"Mark"
Apr 2003
Between here and the
2^{3}×739 Posts 
3771*2^221676+1 Divides F(221670), by PrimeGrid.

20110706, 13:53  #16 
Banned
"Luigi"
Aug 2002
Team Italia
2·2,383 Posts 
43714055 · 2^3337 + 1 divides F(3335), by Nikolay Kamenyuk (FermatSearch).
Luigi 
20110709, 00:38  #17 
"Mark"
Apr 2003
Between here and the
2^{3}·739 Posts 
4479*2^226618+1 divides F226614, again by PrimeGrid.

20110709, 02:08  #18 
Bemusing Prompter
"Danny"
Dec 2002
California
7^{2}×47 Posts 
Dayam, PrimeGrid is sure on a roll...

20110709, 06:27  #19 
May 2011
France
7×23 Posts 
Please
Could you confirm me that I have well understand
F14= 116928085873074369829035993834596371340386703423373313 the only factor find is 319546020820551643220672513 and all primes less than 700000000000000 have been tested http://www.prothsearch.net/fermat.html#Prime John 
20110709, 06:47  #20  
Oct 2010
191 Posts 
Quote:
F_{14} = 2^{2[SUP]14}[/SUP]+1 = 2^{16384}+1 = 116928085873074369829035993834596371340386703423373313 · C4880 Tests were conducted up to 7*10^{14}*2^{16}+1 Another way to write the known factor is: 1784180997819127957596374417642156545110881094717 * 2^{16}+1 Code:
Sat Jul 9 09:28:17 2011 :  Sat Jul 9 09:28:17 2011 : Found a factor for F14: 1784180997819127957596374417642156545110881094717*2^16+1 Sat Jul 9 09:28:17 2011 : Sat Jul 9 09:28:17 2011 : Current k : 1784180997819127957596374417642156545110881094717 Sat Jul 9 09:28:17 2011 : Tested ks : 94718 Sat Jul 9 09:28:17 2011 : Sat Jul 9 09:28:17 2011 : Sieving to : 1742539 [131073. Prime] Sat Jul 9 09:28:17 2011 : Sat Jul 9 09:28:17 2011 : Step : F141 mod (k*2^16+1). Sat Jul 9 09:28:17 2011 : Sat Jul 9 09:28:17 2011 : Work time : 0:00:00:00 Code:
Sat Jul 9 09:35:21 2011 : Speed : Sat Jul 9 09:35:21 2011 : Sat Jul 9 09:35:21 2011 : 22409390 k / second Last fiddled with by Ralf Recker on 20110709 at 07:39 Reason: Notation. 

20110709, 10:54  #21 
Banned
"Luigi"
Aug 2002
Team Italia
2×2,383 Posts 

20110709, 12:16  #22 
Oct 2010
191 Posts 

Thread Tools  
Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
New Generalized Fermat factors  Batalov  Factoring  149  20170220 12:06 
Best case Fermat Factors  yourskadhir  Miscellaneous Math  5  20121212 04:18 
Generalized Fermat factors  why?  siegert81  Factoring  1  20110905 23:00 
Weighted Fermat factors Top 20  Merfighters  Factoring  0  20100413 14:16 
Fermat 12 factors already found?  UberNumberGeek  Factoring  6  20090617 17:22 