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 A110181 #3 Mar 30 2012 18:59:08
%S A110181 1,2,3,6,15,42,131,432,1497,5420,20373,79422,319927,1328764,5677653,
%T A110181 24904584,111961129,515029020,2421047613,11616330342,56829235095,
%U A110181 283211069352,1436529522233,7410596379456,38852645340297
%N A110181 Row sums of number triangle A110180.
%F A110181 a(n)=sum{k=0..n, sum{j=0..floor((n-k)/2), C(n-k, j)C(n-k-j, j)k^j}}.
%K A110181 easy,nonn
%O A110181 0,2
%A A110181 _Paul Barry_, Jul 14 2005