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 A156258 #4 Jun 02 2025 01:20:49 %S A156258 1,0,1,1,0,0,1,0,1,0,0,1,1,0,1,0,0,1,1,0,1,1,0,0,1,0,1,1,0,1,1,0,0,1, %T A156258 0,1,1,0,0,1,0,0,1,0,0,1,1,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,0,0,1,0,1, %U A156258 1,0,1,1,0,0,1,0,0,1,1,0,1,0,0,1,0,0,1,1,0,1,0,0,1,1,0,1,0,0,1,1,0,1,1,0,1 %N A156258 a(n)=(1/2)*(A000002(A078649(n))-A000002(A078649(n)+2)+1). %C A156258 A000002(A078649(n))=A000002(A078649(n)+1) %K A156258 nonn %O A156258 1,1 %A A156258 _Benoit Cloitre_, Feb 07 2009