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 A368787 #6 Jan 06 2024 09:22:20
%S A368787 0,1,7,85,1701,51031,2143303,120024969,8641797769,777761799211,
%T A368787 85553797913211,11293101324543853,1761723806628841069,
%U A368787 320633732806449074559,67333083889354305657391,16159940133445033357773841,4395503716297049073314484753
%N A368787 a(n) = (n+1) * (n!)^2 * Sum_{k=1..n} 1/((k+1) * (k!)^2).
%F A368787 a(0) = 0; a(n) = (n+1) * n * a(n-1) + 1.
%F A368787 a(n) = A228229(n) - (n+1) * (n!)^2.
%o A368787 (PARI) a(n) = (n+1)*n!^2*sum(k=1, n, 1/((k+1)*k!^2));
%Y A368787 Cf. A010790, A066998, A228229.
%K A368787 nonn
%O A368787 0,3
%A A368787 _Seiichi Manyama_, Jan 05 2024