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 A033923 #3 Oct 14 2012 12:58:14 %S A033923 1,1,2,1,2,3,2,3,4,2,3,4,3,4,5,4,5,6,4,5,6,5,6,7,6,7,8,1,2,3,2,3,4,3, %T A033923 4,5,3,4,5,4,5,6,5,6,7,5,6,7,6,7,8,7,8,9,2,3,4,3,4,5,4,5,6,4,5,6,5,6, %U A033923 7,6,7,8,6,7,8,7,8,9,8,9,10,2,3,4,3,4,5,4,5,6,4,5,6,5,6,7,6,7,8,6,7,8,7,8 %N A033923 Base 3 digital convolution sequence. %F A033923 For example, 22 = 211 in base 3, so a(22) = 2a(2)+1a(1)+1a(0). %K A033923 nonn,base %O A033923 1,3 %A A033923 _David W. Wilson_