View Single Post
Old 2006-07-26, 07:37   #25
Citrix's Avatar
Jun 2003

22·397 Posts

Originally Posted by geoff
The current limit for k is 2^32-1. It is not a simple matter to increase that without affecting the sieve speed for general sequences.

It would be possible to write a seperate sieve routine that accepts k=a^b where a and b can each be up to 2^32-1. However there are other parts of the program that will limit the speed as b becomes large. In particular the prime sieve generates all primes and then checks to see if each one is of the correct form, this will become very ineffcient when b gets large, and in any case you will soon need to check factors larger than 2^62 which is the modular multiplication limit for the current code.

Have you tried one of these sieves?: GFNsieve, AthGFNsieve.

The entry is Srsieve.

OK I will stick with this k and not go beyond 2^32

GFNsieve and AthGFNsieve only work with bases<2^32. For me the base is as large as 2^125,000. So I don't think they will work.

Thanks once again for modifying the sieve.

Last fiddled with by Citrix on 2006-07-26 at 07:38
Citrix is offline   Reply With Quote