View Single Post
2011-03-04, 18:26   #15
R.D. Silverman

"Bob Silverman"
Nov 2003
North of Boston

1D4816 Posts

Quote:
 Originally Posted by sascha77 OK. my fault. I forgotten to mention that mersenne Numbers are Numbers of the Form n = 2^{p}-1 with: The variable p is prime !!!!!
That is one definition. You will also find the definition
spread throughout the literature that a Mersenne Number is of the
form 2^n-1 for any n .

Quote:
 Your example with mod 511 -> $511 -> 2^{9}-1$
It is likely that I can find other counter-examples for the case n = prime
if I look hard enough.

It isn't worth my time.