Factoring secondpass ATT:MikeH

[vjs]

Well I'm no expert when it comes to P-1...

So IMHO, I think people should only do them if they feel like it. It's probably a good opportunity for a first timer to grab a small range and see how thinks work. I personally believe we are better off spending our time pushing ahead the firstpass prp with P-1 since each factor found there will eliminate two tests.

As for bounds I wouldn't use very large bounds no more than B1=30K B2=300k for n<4M, I was personally considering B1=20k, B2=160k. Tests should take about 25 minutes on an average machine.

Just remember that these tests are only worth about 1.1 tests at most probably more like 1.05. So for those prime95 default people sieve=49.8 test value=1.1 would be a max honest input.

Oh and just to clairify...

Greenbank, we have never before P-1'ed for n's 1M<n<4M, check the archieve thread... perhaps I don't get the point.