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G.f. satisfies A(x) = 1/(1-x)^2 + x*A(x)^4.
2

%I #7 Jul 30 2023 09:22:00

%S 1,3,15,118,1125,11805,131431,1524090,18208749,222570985,2770129627,

%T 34985756752,447243818573,5775955923428,75245253495035,

%U 987627627396792,13048147674230169,173382031819242855,2315662483861709467,31068798980975635130,418552735866147739185

%N G.f. satisfies A(x) = 1/(1-x)^2 + x*A(x)^4.

%F a(n) = Sum_{k=0..n} binomial(n+5*k+1,6*k+1) * binomial(4*k,k) / (3*k+1).

%o (PARI) a(n) = sum(k=0, n, binomial(n+5*k+1, 6*k+1)*binomial(4*k, k)/(3*k+1));

%Y Cf. A086616, A364620.

%K nonn

%O 0,2

%A _Seiichi Manyama_, Jul 30 2023