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 A071581 #8 Mar 30 2012 18:39:02 %S A071581 3,5,7,6,6,8,7,9,6,4,6,4,3,10,9,4,2,8,6,5,4,9,6,3,-4,-4,-2,2,4,11,2,2, %T A071581 0,2,0,1,0,-2,5,0,-2,0,-7,-5,-4,-2,-10,-14,-14,-12,0,-3,-4,-10,-9,-14, %U A071581 -16,-3,-8,-4,-2,-9,-14,-10,-4,-4,-14,-8,-15,-12,-12,-15,-18,-20,-6,-7 %N A071581 A003656(n)-prime(n). %C A071581 a(n)=0 for n = 33, 35, 37, 40, 42, 51 ... %K A071581 sign %O A071581 1,1 %A A071581 _Benoit Cloitre_, Jun 01 2002 %E A071581 More terms from _Max Alekseyev_, Jun 27 2011