A367050 - OEIS

%I #14 Nov 03 2023 11:20:11

%S 1,1,5,29,198,1469,11518,93875,787392,6752175,58929541,521718814,

%T 4674070602,42296077935,386027716280,3549332631052,32845586854208,

%U 305685481682970,2859315003009776,26866125820982711,253457922829307765,2399910588283502630

%N G.f. satisfies A(x) = 1 + x*A(x)^4 + x^2*A(x)^3.

%F a(n) = Sum_{k=0..floor(n/2)} binomial(3*n-3*k+1,k) * binomial(4*n-5*k,n-2*k)/(3*n-3*k+1).

%o (PARI) a(n) = sum(k=0, n\2, binomial(3*n-3*k+1, k)*binomial(4*n-5*k, n-2*k)/(3*n-3*k+1));

%Y Cf. A365178, A365180, A365181, A365182, A365183, A367041, A367048, A367049.

%K nonn

%O 0,3

%A _Seiichi Manyama_, Nov 03 2023