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Primes congruent to 2^k+1 (mod 2^(k+1)), where k is any odd integer >=1.
4

%I #8 Aug 02 2015 02:07:54

%S 3,7,11,19,23,31,41,43,47,59,67,71,73,79,83,89,97,103,107,127,131,137,

%T 139,151,163,167,179,191,199,211,223,227,233,239,251,263,271,281,283,

%U 307,311,313,331,347,353,359,367,379,383,409,419,431,439,443,457,463

%N Primes congruent to 2^k+1 (mod 2^(k+1)), where k is any odd integer >=1.

%C Lim_{x -> inf.} the number of terms < x in A160216/A160215 => 2. - _Robert G. Wilson v_, May 31 2009

%F A000040 \ A160215.

%F {prime(k) : A023506(k) is odd}. - _R. J. Mathar_, May 08 2009

%t fQ[n_] := Mod[ Flatten[ FactorInteger[n - 1]] [[2]], 2] == 1; Select[ Prime@ Range@ 90, fQ@# &] (* _Robert G. Wilson v_, May 31 2009 *)

%Y Cf. A000040, A160215.

%K nonn

%O 1,1

%A _Vladimir Shevelev_, May 04 2009

%E Edited by _R. J. Mathar_, May 08 2009

%E More terms from _Robert G. Wilson v_, May 31 2009