This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A160216 #8 Aug 02 2015 02:07:54
%S A160216 3,7,11,19,23,31,41,43,47,59,67,71,73,79,83,89,97,103,107,127,131,137,
%T A160216 139,151,163,167,179,191,199,211,223,227,233,239,251,263,271,281,283,
%U A160216 307,311,313,331,347,353,359,367,379,383,409,419,431,439,443,457,463
%N A160216 Primes congruent to 2^k+1 (mod 2^(k+1)), where k is any odd integer >=1.
%C A160216 Lim_{x -> inf.} the number of terms < x in A160216/A160215 => 2. - _Robert G. Wilson v_, May 31 2009
%F A160216 A000040 \ A160215.
%F A160216 {prime(k) : A023506(k) is odd}. - _R. J. Mathar_, May 08 2009
%t A160216 fQ[n_] := Mod[ Flatten[ FactorInteger[n - 1]] [[2]], 2] == 1; Select[ Prime@ Range@ 90, fQ@# &] (* _Robert G. Wilson v_, May 31 2009 *)
%Y A160216 Cf. A000040, A160215.
%K A160216 nonn
%O A160216 1,1
%A A160216 _Vladimir Shevelev_, May 04 2009
%E A160216 Edited by _R. J. Mathar_, May 08 2009
%E A160216 More terms from _Robert G. Wilson v_, May 31 2009