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 A368587 #8 Dec 31 2023 10:22:06
%S A368587 0,1,4,9,20,26,96,-210,2472,-20961,211612,-2324729,27901116,
%T A368587 -362708320,5077925048,-76168864092,1218701840976,-20717931276243,
%U A368587 372922762998708,-7085532496941803,141710649938878564,-2975923648716396714,65470320271760793488
%N A368587 a(n) = n! * Sum_{k=0..n} (-1)^(n-k) * binomial(k+4,5) / k!.
%F A368587 a(0) = 0; a(n) = -n*a(n-1) + binomial(n+4,5).
%F A368587 E.g.f.: x * (1+2*x+x^2+x^3/6+x^4/120) * exp(x) / (1+x).
%o A368587 (PARI) my(N=30, x='x+O('x^N)); concat(0, Vec(serlaplace(x*sum(k=0, 4, binomial(4, k)*x^k/(k+1)!)*exp(x)/(1+x))))
%Y A368587 Cf. A009574, A368585, A368586.
%Y A368587 Cf. A368576.
%K A368587 sign,easy
%O A368587 0,3
%A A368587 _Seiichi Manyama_, Dec 31 2023