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 A056731 #3 Mar 30 2012 16:48:51 %S A056731 2,1,1,2,1,1,1,2,1,1,1,1,2,1,1,1,1,1,1,2,1,1,1,1,1,1,1,2,1,1,1,1,1,1, %T A056731 1,1,2,1,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,1, %U A056731 1,1,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1 %N A056731 First differences of A030124. %Y A056731 Cf. A005228, A030124, A056738. %K A056731 nonn,easy %O A056731 1,1 %A A056731 _N. J. A. Sloane_, Aug 31 2000