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 A358852 #16 Dec 10 2023 09:14:10
%S A358852 1,1,2,12,32,140,1512,6384,44928,749088,4299840,42546240,974695680,
%T A358852 7061783040,90598072320,2640888230400,23099489280000,364696083763200,
%U A358852 12881138586624000,132004210918809600,2475855534329856000,102587486964092928000,1205260977814806528000
%N A358852 a(n) = n!*Sum_{m=0..floor(n/3)} 1/binomial(n-m,2*m).
%H A358852 Seiichi Manyama, <a href="/A358852/b358852.txt">Table of n, a(n) for n = 0..449</a>
%F A358852 E.g.f.: ((sqrt(x)*(x^3-2*x^2+x+1)*log((-x^(3/2)-1)/(x^(3/2)-1)))/2+(1-x)*x*log((1-x)^3*(x^2+x+1)))/(-x^3+2*x^2-x+1)^2+(3*x^2+1)/((x-1)*(x^2+x+1)*(x^3-2*x^2+x-1)).
%o A358852 (Maxima)
%o A358852 a(n):=n!*sum(1/(binomial(n-m,2*m)),m,0,floor(n/3));
%o A358852 (PARI) a(n) = n!*sum(m=0, n\3, 1/binomial(n-m,2*m)); \\ _Michel Marcus_, Dec 03 2022
%Y A358852 Cf. A358446.
%K A358852 nonn
%O A358852 0,3
%A A358852 _Vladimir Kruchinin_, Dec 02 2022