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Old 2007-01-10, 18:55   #4
Xentar's Avatar
Sep 2006

11·17 Posts

Originally Posted by fatphil View Post
22*22^511+1 is not prime.
22*22^2047+1 is not prime.
22*22^3583+1 is not prime.
22*22^6655+1 is not prime.

Are you sure you know what you're doing?
Those are 22^n+1, which can only ever be prime if n=2^m for some n, namely generalised Fermat numbers.
eh.. is it the same with
18 * 18^n+1 ?
and if not, could you please try to explain it to me? (Yea, I'm trying to learn the math behind these projects )
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