|
%I #4 Mar 30 2012 17:34:21
%S 3,5,7,11,17,73,137,257,65537
%N Primes that have one of the forms 2^(2^n) + 1, 2^(2^n - 1) + 2^(2^(n + 1) - 1) + 1 or (2^(2^n) + 1 + 2^(2^(n + 1) - 1) + 1)/2.
%t a = Union[Flatten[Table[{2^(2^n) + 1, 2^(2^n - 1) + 2^(2^(n + 1) - 1) + 1, (2^(2^n) + 1 + 2^(2^(n + 1) - 1) + 1)/2}, {n, 0, 10}]]] aout = Flatten[Table[If[PrimeQ[a[[n]]], a[[n]], {}], {n, 1, Length[a]}]]
%Y Cf. A019434.
%K nonn
%O 1,1
%A _Roger L. Bagula_, May 31 2006
%E Edited by _N. J. A. Sloane_, Jun 03 2006
|
