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%I #11 Aug 24 2023 07:48:27
%S 1,3,27,295,3648,48513,677450,9797031,145458252,2204380144,
%T 33960095667,530268482913,8373331428836,133484219528982,
%U 2145376940485452,34725549386905863,565567039020594492,9261756210015412356,152410211630410153468
%N G.f. satisfies A(x) = ( 1 + x*A(x)^2*(1 + x*A(x))^2 )^3.
%F If g.f. satisfies A(x) = ( 1 + x*A(x)^2*(1 + x*A(x))^s )^t, then a(n) = Sum_{k=0..n} binomial(t*(n+k+1),k) * binomial(s*k,n-k)/(n+k+1).
%o (PARI) a(n, s=2, t=3) = sum(k=0, n, binomial(t*(n+k+1), k)*binomial(s*k, n-k)/(n+k+1));
%Y Cf. A214372, A365155.
%K nonn
%O 0,2
%A _Seiichi Manyama_, Aug 23 2023
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