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 A055221 #4 Mar 30 2012 18:57:04 %S A055221 1,7,36,157,625,2343,8427,29406,100296,336066,1110300,3626559, %T A055221 11734557,37673295,120150909,381040101,1202559732,3779328996, %U A055221 11833845967,36934571140,114947180946,356828242618,1105180433704 %N A055221 T(2n+5,n), array T as in A055216. %K A055221 nonn %O A055221 0,2 %A A055221 _Clark Kimberling_, May 07 2000