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 A110136 #10 Dec 03 2016 12:18:22
%S A110136 1,3,9,31,115,447,1803,7499,32069,140795,633981,2925671,13826405,
%T A110136 66861107,330544409,1669024071,8598951451,45160258503,241540648011,
%U A110136 1314519420803,7273377034547,40886211572271,233344325395327
%N A110136 Sums of antidiagonals of number square A110135.
%C A110136 Also row sums of A110135, when read as number triangle.
%F A110136 a(n) = Sum_{j=0..floor((n-k)/2)} binomial(n-k,j)*binomial(2(n-k-j),n-k)*k^j.
%K A110136 easy,nonn
%O A110136 0,2
%A A110136 _Paul Barry_, Jul 13 2005