A379284 G.f. A(x) satisfies A(x) = 1/((1 - x*A(x)^2) * (1 - x*A(x)^4)).

1, 2, 15, 158, 1943, 26099, 371128, 5491868, 83692617, 1304579981, 20703125143, 333366138381, 5433036837372, 89448269251685, 1485469625972490, 24854484773368344, 418581393456669989, 7090045259711970090, 120706208890692261466, 2064356606197948427512, 35449776962011108029539

Offset

0,2

Links

Table of n, a(n) for n=0..20.

Formula

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

Prog

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

Crossrefs

Cf. A118969, A199475, A379209, A379285, A379286, A379287.

Sequence in context: A239107 A124548 A324463 * A139085 A268070 A204679

Adjacent sequences: A379281 A379282 A379283 * A379285 A379286 A379287

Keyword

nonn,new

Author

Seiichi Manyama, Dec 19 2024

Status

approved