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 A057550 #2 May 01 2014 02:48:30 %S A057550 1,2,1,4,1,2,1,1,9,1,2,1,1,4,1,2,1,1,2,1,1,1,23,1,2,1,1,4,1,2,1,1,2,1, %T A057550 1,1,9,1,2,1,1,4,1,2,1,1,2,1,1,1,4,1,2,1,1,2,1,1,1,2,1,1,1,1,65,1,2,1, %U A057550 1,4,1,2,1,1,2,1,1,1,9,1,2,1,1,4,1,2,1,1,2,1,1,1,4,1,2,1,1,2,1,1,1,2,1 %N A057550 First differences of A057549. %Y A057550 Terms a(A014138[n]) seem to give A014137[n+1]. Cf. A057551. %K A057550 nonn %O A057550 0,2 %A A057550 _Antti Karttunen_, Sep 07 2000