A366241 - OEIS

%I #10 Oct 05 2023 08:35:13

%S 1,2,10,72,552,4593,40185,364413,3395217,32305005,312589540,

%T 3066565720,30430287693,304907935707,3080617021926,31349533179726,

%U 321038696185371,3305935381202847,34211612434972446,355605873560512974,3710978684625678870

%N G.f. A(x) satisfies A(x) = 1 + x + x*(1 + x)^4*A(x)^3.

%F a(n) = Sum_{k=0..n} binomial(6*k+1,n-k) * binomial(3*k,k)/(2*k+1).

%o (PARI) a(n) = sum(k=0, n, binomial(6*k+1, n-k)*binomial(3*k, k)/(2*k+1));

%Y Cf. A364336, A366239, A366240.

%Y Cf. A366222.

%K nonn

%O 0,2

%A _Seiichi Manyama_, Oct 05 2023