20150124, 23:02  #1 
Einyen
Dec 2003
Denmark
3,037 Posts 
P1/P+1 on Fermat numbers
Are there any records of how high P1 and P+1 have been taken on the "small" fermat numbers F12 to F26 ?

20150125, 03:08  #2 
Romulan Interpreter
Jun 2011
Thailand
5^{2}·7·53 Posts 

20150125, 06:27  #3 
"Curtis"
Feb 2005
Riverside, CA
2·2,339 Posts 
Since P1 runs at nearly ten times the speed of an ECM curve with the same bounds, it always makes sense to do P1 for any candidate where ECM is useful. This relative speedup is why it is often suggested to do P1 with B1 ten times higher than the B1level of ECM effort.

Thread Tools  
Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
ecm with Fermat numbers  ET_  FermatSearch  1  20160802 19:40 
Generalized Fermat Numbers  ET_  Programming  4  20080623 07:59 
Are there any Fermat numbers that might be prime?  jasong  Math  39  20071027 23:11 
LLT numbers, linkd with Mersenne and Fermat numbers  T.Rex  Math  4  20050507 08:25 
Fermat Numbers  devarajkandadai  Math  8  20040727 12:27 