A366099 Expansion of (1/x) * Series_Reversion( x*(1+x-x^4)/(1+x)^3 ).

1, 2, 5, 14, 43, 143, 507, 1885, 7247, 28523, 114190, 463179, 1898892, 7855615, 32754687, 137520639, 580920600, 2467305352, 10530055735, 45135757683, 194224957674, 838729701308, 3633559928326, 15787558766909, 68780335280091, 300391273651651, 1314927603572310

Offset

0,2

Links

Table of n, a(n) for n=0..26.

Formula

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

Prog

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

Crossrefs

Cf. A366098, A366100.

Sequence in context: A005425 A035349 A155888 * A254314 A249562 A006789

Adjacent sequences: A366096 A366097 A366098 * A366100 A366101 A366102

Keyword

nonn

Author

Seiichi Manyama, Sep 29 2023

Status

approved