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 A365845 #9 Sep 20 2023 10:00:58
%S A365845 1,8,97,1400,22243,375584,6614508,120136984,2234022775,42322629960,
%T A365845 813939319697,15849232257824,311858145053076,6191083938051840,
%U A365845 123852349440862504,2494251111318893400,50526944132627936127,1028872756710478785560
%N A365845 Expansion of (1/x) * Series_Reversion( x*(1-x)^5/(1+x)^3 ).
%F A365845 a(n) = (1/(n+1)) * Sum_{k=0..n} binomial(5*n+k+4,k) * binomial(3*(n+1),n-k).
%o A365845 (PARI) a(n) = sum(k=0, n, binomial(5*n+k+4, k)*binomial(3*(n+1), n-k))/(n+1);
%Y A365845 Cf. A007297, A365842, A365843, A365844.
%K A365845 nonn
%O A365845 0,2
%A A365845 _Seiichi Manyama_, Sep 20 2023