A366455 G.f. A(x) satisfies A(x) = 1 + x + x/A(x)^(5/2).

1, 2, -5, 30, -215, 1710, -14516, 128830, -1180920, 11093830, -106245975, 1033454774, -10181848705, 101394979530, -1018972470275, 10320779179380, -105250097458410, 1079767027094630, -11136159773691830, 115395278542757580, -1200814926210284360

Offset

0,2

Links

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

Formula

G.f.: A(x) = 1/B(-x) where B(x) is the g.f. of A366401.

a(n) = (-1)^(n-1) * Sum_{k=0..n} binomial(7*k/2-1,k) * binomial(n+5*k/2-2,n-k) / (7*k/2-1).

Prog

(PARI) a(n) = (-1)^(n-1)*sum(k=0, n, binomial(7*k/2-1, k)*binomial(n+5*k/2-2, n-k)/(7*k/2-1));

Crossrefs

Cf. A112478, A364393, A364407, A364408, A364409, A366266, A366267, A366268, A366452, A366453, A366454, A366456.

Cf. A366401.

Sequence in context: A209325 A019027 A019031 * A140786 A369726 A129951

Adjacent sequences: A366452 A366453 A366454 * A366456 A366457 A366458

Keyword

sign

Author

Seiichi Manyama, Oct 10 2023

Status

approved