A365845 - OEIS

%I #9 Sep 20 2023 10:00:58

%S 1,8,97,1400,22243,375584,6614508,120136984,2234022775,42322629960,

%T 813939319697,15849232257824,311858145053076,6191083938051840,

%U 123852349440862504,2494251111318893400,50526944132627936127,1028872756710478785560

%N Expansion of (1/x) * Series_Reversion( x*(1-x)^5/(1+x)^3 ).

%F a(n) = (1/(n+1)) * Sum_{k=0..n} binomial(5*n+k+4,k) * binomial(3*(n+1),n-k).

%o (PARI) a(n) = sum(k=0, n, binomial(5*n+k+4, k)*binomial(3*(n+1), n-k))/(n+1);

%Y Cf. A007297, A365842, A365843, A365844.

%K nonn

%O 0,2

%A _Seiichi Manyama_, Sep 20 2023