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 A090450 #4 Oct 10 2012 03:11:22 %S A090450 1,2,5,22,221,5556,352897,56909000,23456163817,24862388706622, %T A090450 68125408037874461,484697617517152241192,8987761653844408528516645, %U A090450 435751632681268773059903563592,55389930392445599773550918556967161 %N A090450 Row sums of triangle A090447. %F A090450 a(n)=sum(A090447(n, m), m=0..n), n>=0. %Y A090450 Cf. A090451 (alternating row sums). %K A090450 nonn,easy %O A090450 0,2 %A A090450 _Wolfdieter Lang_, Dec 23 2003