A367057 G.f. satisfies A(x) = 1 + x*A(x)^3 + x^3*A(x).

1, 1, 3, 13, 59, 294, 1549, 8477, 47715, 274468, 1606284, 9533595, 57247969, 347169053, 2123148153, 13079296531, 81087402683, 505543820304, 3167578950478, 19935616736595, 125971005957924, 798883392476824, 5083047458454395, 32439034490697090

Offset

0,3

Links

Table of n, a(n) for n=0..23.

Formula

a(n) = Sum_{k=0..floor(n/3)} binomial(2*n-5*k+1,k) * binomial(3*n-8*k,n-3*k)/(2*n-5*k+1).

Prog

(PARI) a(n) = sum(k=0, n\3, binomial(2*n-5*k+1, k)*binomial(3*n-8*k, n-3*k)/(2*n-5*k+1));

Crossrefs

Cf. A366676, A367058, A367059, A367060, A367061, A367062.

Sequence in context: A151234 A330799 A379159 * A317776 A145942 A331517

Adjacent sequences: A367054 A367055 A367056 * A367058 A367059 A367060

Keyword

nonn

Author

Seiichi Manyama, Nov 04 2023

Status

approved