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 A043268 #4 Mar 30 2012 18:56:34 %S A043268 0,1,2,3,4,5,6,7,8,2,4,6,8,10,12,14,16,2,3,4,5,6,7,8,9,10,4,5,6,7,8,9, %T A043268 10,11,12,6,7,8,9,10,11,12,13,14,8,9,10,11,12,13,14,15,16,10,11,12,13, %U A043268 14,15,16,17,18,12,13,14,15,16,17,18,19,20,14 %N A043268 Sum of digits of n-th base 9 palindrome. %Y A043268 A029955 (base 9 palindromes) %K A043268 nonn,base %O A043268 1,3 %A A043268 _Clark Kimberling_