A377267 G.f. satisfies A(x) = 1/(1 - 9*x*A(x))^(2/3).

1, 6, 81, 1386, 26676, 551124, 11939967, 267647490, 6155681103, 144442697256, 3444310087155, 83222570083068, 2033143391152440, 50136558534943776, 1246312401751305306, 31197886757177379570, 785732617740674763684, 19896044539519213482690

Offset

0,2

Links

Table of n, a(n) for n=0..17.

Index entries for reversions of series

Formula

G.f.: (1/x) * Series_Reversion( x*(1-9*x)^(2/3) ).

a(n) = 9^n * binomial(5*n/3 - 1/3,n)/(n+1).

G.f.: B(x)^2, where B(x) is the g.f. of A245114.

Prog

(PARI) a(n) = 9^n*binomial(5*n/3-1/3, n)/(n+1);

Crossrefs

Cf. A078532, A245114, A377262.

Sequence in context: A197076 A373939 A377262 * A234872 A064341 A372321

Adjacent sequences: A377264 A377265 A377266 * A377268 A377269 A377270

Keyword

nonn,easy

Author

Seiichi Manyama, Oct 22 2024

Status

approved