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 A156259 #4 Jun 02 2025 01:20:55 %S A156259 0,1,0,0,1,1,0,1,0,1,1,0,0,1,0,1,1,0,0,1,0,0,1,1,0,1,0,0,1,0,0,1,1,0, %T A156259 1,0,0,1,1,0,1,1,0,1,1,0,0,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,1,1,0,1,0, %U A156259 0,1,0,0,1,1,0,1,1,0,0,1,0,1,1,0,1,1,0,0,1,0,1,1,0,0,1,0,1,1,0,0,1,0,0,1,0 %N A156259 a(n)=(1/2)*(A000002(A078649(n)+2)-A000002(A078649(n))+1). %C A156259 A000002(A078649(n))=A000002(A078649(n)+1) %K A156259 nonn %O A156259 1,1 %A A156259 _Benoit Cloitre_, Feb 07 2009