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 A368793 #8 Jan 06 2024 09:21:56
%S A368793 0,1,6,45,454,5907,94518,1795849,39508686,987717159,27656080462,
%T A368793 857338494333,29149508807334,1078531825871371,43141273034854854,
%U A368793 1855074740498758737,85333438062942901918,4181338465084202193999,217429600184378514087966
%N A368793 a(n) = (3*n-2)!!! * Sum_{k=0..n} k/(3*k-2)!!!.
%F A368793 a(0) = 0; a(n) = (3*n-2)*a(n-1) + n.
%o A368793 (PARI) a007559(n) = prod(k=1, n, 3*k-2);
%o A368793 a(n) = a007559(n)*sum(k=0, n, k/a007559(k));
%Y A368793 Cf. A007559, A368792.
%K A368793 nonn
%O A368793 0,3
%A A368793 _Seiichi Manyama_, Jan 05 2024