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Old 2020-08-14, 22:05   #2
R. Gerbicz
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"Robert Gerbicz"
Oct 2005

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Originally Posted by bhelmes View Post
if I know the factorisation or a part of the factorisation of Mp-1
do I have any advantages for checking the primality ?
Probably there is no advantage for that, but any odd factor of Mp-1 could give a non-trival factor of another Mersenne number (with prime index),
since r|Mp-1=2*(2^(p-1)-1).

Last fiddled with by R. Gerbicz on 2020-08-14 at 22:07
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