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 A091564 #2 Mar 30 2012 17:37:13 %S A091564 1,2,1,4,5,2,3,8,7,10,9,4,7,6,5,16,17,14,15,20,17,18,19,8,9,14,11,12, %T A091564 17,10,11,32,31,34,33,28,31,30,29,40,39,34,37,36,31,38,37,16,19,18,17, %U A091564 28,27,22,25,24,23,34,29,20,31,22,21,64,65,62,63,68,65,66,67,56,57,62 %N A091564 Row sums of A090174. %Y A091564 Cf. A053985. %K A091564 nonn %O A091564 0,2 %A A091564 _Christian G. Bower_, Jan 20 2004