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 A034728 #5 Mar 30 2012 18:35:33 %S A034728 1,9,18,18,27,34,43,52,63,69,81,89,99,106,113,117,126,134,147 %N A034728 Sum of digits of A034727(n). %Y A034728 Cf. A034726, A034727. %K A034728 nonn,base %O A034728 1,2 %A A034728 _David W. Wilson_