A365695 G.f. satisfies A(x) = 1 + x^3*A(x)^5 / (1 - x*A(x)).

1, 0, 0, 1, 1, 1, 6, 12, 19, 62, 156, 318, 852, 2254, 5262, 13441, 35543, 88772, 226880, 596937, 1539188, 3980364, 10468270, 27410289, 71702956, 189169352, 499529048, 1318355542, 3493861461, 9278408639, 24647900618, 65620808508, 175037591303, 467277998136

Offset

0,7

Links

Table of n, a(n) for n=0..33.

Formula

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

Prog

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

Crossrefs

Cf. A023426, A023432, A054514, A114997, A365694.

Sequence in context: A087883 A218438 A162416 * A233586 A332543 A348914

Adjacent sequences: A365692 A365693 A365694 * A365696 A365697 A365698

Keyword

nonn

Author

Seiichi Manyama, Sep 16 2023

Status

approved