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 A033927 #3 Oct 14 2012 12:58:14 %S A033927 1,1,2,3,4,5,6,1,2,3,4,5,6,7,2,3,4,5,6,7,8,3,4,5,6,7,8,9,4,5,6,7,8,9, %T A033927 10,5,6,7,8,9,10,11,6,7,8,9,10,11,12,2,3,4,5,6,7,8,3,4,5,6,7,8,9,4,5, %U A033927 6,7,8,9,10,5,6,7,8,9,10,11,6,7,8,9,10,11,12,7,8,9,10,11,12,13,8,9,10,11 %N A033927 Base 7 digital convolution sequence. %F A033927 For example, 287 = 560 in base 7, so a(287) = 5a(2)+6a(1)+0a(0). %K A033927 nonn,base %O A033927 1,3 %A A033927 _David W. Wilson_