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 A023563 #3 Mar 30 2012 18:55:52 %S A023563 0,1,3,4,7,11,13,17,21,26,31,35,41,47,53,59,66,73,79,86,95,102,111, %T A023563 119,126,136,144,154,163,173,184,193,202,212,223,235,245,257,270,279, %U A023563 291,302,313,327,339,351,366,378,391,403,416,431,443,456,471 %N A023563 Convolution of A023531 and A000201. %K A023563 nonn %O A023563 1,3 %A A023563 _Clark Kimberling_