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 A047003 #4 Mar 30 2012 18:56:51 %S A047003 1,2,2,7,30,113,442,1692,6542,25213,97548,377617,1465010,5690787, %T A047003 22140830,86250091,336416094,1313641661,5134950280,20091508863, %U A047003 78682553016,308392187964,1209658474836,4748241492783,18650595931506 %N A047003 T(n,n-1), array T given by A047000. %K A047003 nonn %O A047003 1,2 %A A047003 _Clark Kimberling_