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 A047007 #4 Mar 30 2012 18:56:51 %S A047007 1,3,9,30,103,366,1323,4859,18033,67531,254620,965592,3679039, %T A047007 14074126,54023919,207985518,802774173,3105514305,12037590980, %U A047007 46743091795,181796906808,708073498446,2761428873186,10782065189898,42144216934185 %N A047007 T(n,n+2), array T given by A047000. %K A047007 nonn %O A047007 0,2 %A A047007 _Clark Kimberling_