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ATH 2015-01-24 23:02

P-1/P+1 on Fermat numbers
 
Are there any records of how high P-1 and P+1 have been taken on the "small" fermat numbers F12 to F26 ?

LaurV 2015-01-25 03:08

[QUOTE=ATH;393457]Are there any records of how high P-1 and P+1 have been taken on the "small" fermat numbers F12 to F26 ?[/QUOTE]
Does it make sense, considering the huge qty of ECM done? (it is not rhetoric, it is a sincere question)

VBCurtis 2015-01-25 06:27

[QUOTE=LaurV;393469]Does it make sense, considering the huge qty of ECM done? (it is not rhetoric, it is a sincere question)[/QUOTE]

Since P-1 runs at nearly ten times the speed of an ECM curve with the same bounds, it always makes sense to do P-1 for any candidate where ECM is useful. This relative speedup is why it is often suggested to do P-1 with B1 ten times higher than the B1-level of ECM effort.


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