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Old 2010-10-11, 17:58   #13
lorgix's Avatar
Sep 2010

3×5×41 Posts

Originally Posted by Mini-Geek View Post
Even faster with B1=34631 and no stage 2. This 78 bit prime factor can be found in ~95 seconds on one core of a modern CPU. Pretty incredible.
Yes, didn't think it through.

I'm doing a large number of P-1 in that exponent area with B1~ double the above, and no stage 2. Might add on stage 2 later. But as low as the limits are on some exponents in the area I think this might be a fairly effective approach.

On the other end we have M234473 with its 2kp+1=750020570278149061867959407

k= 41*234,473*161,503,549*241,537,413,779

Good luck finding that with P-1!

Would be nice to hear other more or less extreme examples, maybe that has/deserves a thread of its own.

Last fiddled with by lorgix on 2010-10-11 at 18:00 Reason: typo
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