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Old 2008-10-31, 11:50   #3
NBtarheel_33
 
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"Nathan"
Jul 2008
Maryland, USA

5·223 Posts
Thumbs up That's just what I was looking for

Thanks, Jacob. This should almost be made into a sticky, at least in the LMH forum. It makes sense that there's no information about numbers over M5xx,000,000; I believe the current version of Prime95 will not do an LL test over M596,000,000.

You really gain an appreciation for just how expensive LL testing on these kinds of numbers is when you consider that weeks, or even *months* of trial factoring makes good sense. Like on M999,999,937, I took a day to get to 73, so it would be roughly 2+4+8+16+32+64+128+256 = 510 days, or just under 1 1/2 *YEARS* :surprised just on trial factoring to 81 bits (and I bet M999,999,937 ought to go out to 84 or 85 bits, really). Wow. Then again 1 1/2 years factoring is just a brief prelude to the 70-80 year LL test my computer estimated for M999,999,937. I think I'll stick with my 30M exponents for now.

Thanks again for the info!
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