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 A304338 #9 May 11 2018 12:03:48
%S A304338 1,1,4,26,239,2902,44441,830636,18495910,481474188,14432543299,
%T A304338 492063896964,18885525411110,808850019798316,38368738864146619,
%U A304338 2002743853356179552,114374154959904537521,7110312727864509410026,479017371580348640009295
%N A304338 Row sums of A304336.
%F A304338 a(n) = Sum_{k=0..n} Sum_{j=0..k} (-1)^j*binomial(2*k,j)*(k-j)^(2*n) / (k!)^2.
%p A304338 A304338 := n -> add(add((-1)^j*binomial(2*k,j)*(k-j)^(2*n), j=0..k)/(k!)^2, k=0..n): seq(A304338(n), n=0..18);
%o A304338 (PARI) a(n) = sum(k=0, n, sum(j=0, k, (-1)^j*binomial(2*k,j)*(k-j)^(2*n)) / (k!)^2); \\ _Michel Marcus_, May 11 2018
%Y A304338 Cf. A304330, A304334, A304336.
%K A304338 nonn
%O A304338 0,3
%A A304338 _Peter Luschny_, May 11 2018