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 A360818 #10 Feb 22 2023 10:19:45
%S A360818 1,0,1,1,17,65,922,7074,106183,1248479,21144289,331763177,6441011484,
%T A360818 124904347404,2773880604749,63538143151589,1600211849569585,
%U A360818 42076439530000297,1189408501356380558,35214128238218917974,1106088535644470694779
%N A360818 Expansion of Sum_{k>=0} ( (k*x)^2 / (1 - k*x) )^k.
%F A360818 a(n) = Sum_{k=0..floor(n/2)} k^n * binomial(n-k-1,n-2*k).
%o A360818 (PARI) my(N=30, x='x+O('x^N)); Vec(sum(k=0, N, ((k*x)^2/(1-k*x))^k))
%o A360818 (PARI) a(n) = sum(k=0, n\2, k^n*binomial(n-k-1, n-2*k));
%Y A360818 Cf. A195242, A360819.
%Y A360818 Cf. A360708.
%K A360818 nonn
%O A360818 0,5
%A A360818 _Seiichi Manyama_, Feb 21 2023