A371495 G.f. A(x) satisfies A(x) = 1 / (1 - x*A(x) / (1+x))^3.

1, 3, 12, 64, 381, 2430, 16227, 112008, 792717, 5721165, 41945373, 311529831, 2338909219, 17722127580, 135346614906, 1040779011412, 8051611785006, 62620659604659, 489339248275242, 3840135625895886, 30251386980891657, 239138782521553659, 1896380840948325606

Offset

0,2

Links

Table of n, a(n) for n=0..22.

Formula

a(n) = Sum_{k=0..n} (-1)^(n-k) * binomial(n-1,n-k) * binomial(4*k+2,k)/(k+1).

Prog

(PARI) a(n) = sum(k=0, n, (-1)^(n-k)*binomial(n-1, n-k)*binomial(4*k+2, k)/(k+1));

Crossrefs

Cf. A001006, A371494, A371496.

Cf. A006632.

Sequence in context: A365122 A233397 A206226 * A326809 A326557 A308204

Adjacent sequences: A371492 A371493 A371494 * A371496 A371497 A371498

Keyword

nonn

Author

Seiichi Manyama, Mar 25 2024

Status

approved