Source code for a siever is here:

C factorial prime siever.

You're on your own; this is entirely in the public domian -
change it, tweak it, whatever it.

The results of sieving n!+/-1 for n=30000 to 100000 up to p=6G are here:

factorial composite list

If you are interested in these things, then you should be part of
Nuutti Kuosa's coordinated factorial
prime search.

If you find a large prime having used these files, can you at least make mention of me, and my beloved Alpha, which did the sieving!

Cheers,

Phil Carmody, 24/04/2002