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 A368574 #13 Dec 31 2023 10:22:52
%S A368574 0,1,6,28,132,695,4226,29666,237448,2137197,21372190,235094376,
%T A368574 2821132876,36674727843,513446190362,7701692856110,123227085698576,
%U A368574 2094860456876761,37707488223782838,716442276251875252,14328845525037506580,300905756025787639951,6619926632567328080946
%N A368574 a(n) = n! * Sum_{k=0..n} binomial(k+2,3) / k!.
%F A368574 a(0) = 0; a(n) = n*a(n-1) + binomial(n+2,3).
%F A368574 E.g.f.: x * (1+x+x^2/6) * exp(x) / (1-x).
%o A368574 (PARI) my(N=30, x='x+O('x^N)); concat(0, Vec(serlaplace(x*sum(k=0, 2, binomial(2, k)*x^k/(k+1)!)*exp(x)/(1-x))))
%Y A368574 Cf. A007526, A103519, A368575, A368576.
%Y A368574 Cf. A000292, A337001.
%K A368574 nonn,easy
%O A368574 0,3
%A A368574 _Seiichi Manyama_, Dec 31 2023