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 A190908 #7 Mar 28 2020 06:09:01
%S A190908 1,2,5,15,49,163,549,1875,6477,22571,79213,279631,991985,3533707,
%T A190908 12632909,45301795,162890781,587091795,2120442517,7672891151,
%U A190908 27811187377,100956896179,366983328885,1335662387699
%N A190908 a(n) = Sum{0<=k<=n} binomial(n+k, n-k) * k! / (floor(k/2)! * floor((k+2)/2)!).
%C A190908 Row sums of A190907.
%p A190908 A190908 := n -> add(binomial(n+k,n-k)*k!/(iquo(k,2)!*iquo(k+2,2)!), k=0..n): seq(A190908(n), n=0..24);
%K A190908 nonn
%O A190908 0,2
%A A190908 _Peter Luschny_, May 24 2011