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 A118952 #6 Mar 30 2012 18:50:54 %S A118952 0,0,0,0,0,1,1,0,0,1,1,0,1,0,1,0,0,1,1,0,1,0,1,0,0,0,1,0,1,0,0,0,0,1, %T A118952 1,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,0,0,0,0,1,0,1,0,0,1,1,0, %U A118952 1,0,1,0,0,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,0,0,0,0,1,0,1,0,0,0,0,0,1,0,0,0,1 %N A118952 Characteristic function of numbers that can be written as p+2^k, where p is prime and p less than 2^k (A118957). %C A118952 0 <= a(n) <= 1, a(n) <= A109925(n); %C A118952 a(A118956(n)) = 0, a(A118957(n)) = 1; %C A118952 A118953(n) = a(A000040(n)). %H A118952 <a href="/index/Ch#char_fns">Index entries for characteristic functions</a> %K A118952 nonn %O A118952 1,1 %A A118952 _Reinhard Zumkeller_, May 07 2006