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 A360787 #13 Feb 21 2023 02:09:20
%S A360787 1,1,1,3,13,40,177,965,4733,28103,184065,1191888,8713549,67005689,
%T A360787 528870257,4526024267,40051790333,368513578472,3583302492545,
%U A360787 35868588067501,373781214260749,4052932682659599,45218033687522481,523234757502985824,6245693941097387773
%N A360787 Expansion of Sum_{k>=0} x^k / (1 - (k*x)^2)^(k+1).
%F A360787 a(n) = Sum_{k=0..floor(n/2)} (n-2*k)^(2*k) * binomial(n-k,k).
%t A360787 Join[{1}, Table[Sum[Binomial[n-k,k] * (n-2*k)^(2*k), {k,0,n/2}], {n,1,30}]] (* _Vaclav Kotesovec_, Feb 21 2023 *)
%o A360787 (PARI) my(N=30, x='x+O('x^N)); Vec(sum(k=0, N, x^k/(1-(k*x)^2)^(k+1)))
%o A360787 (PARI) a(n) = sum(k=0, n\2, (n-2*k)^(2*k)*binomial(n-k, k));
%Y A360787 Cf. A000248, A360788.
%Y A360787 Cf. A360782, A360592.
%K A360787 nonn,easy
%O A360787 0,4
%A A360787 _Seiichi Manyama_, Feb 20 2023