A377268 G.f. satisfies A(x) = (1 - 9*x*A(x))^(1/3).

1, -3, 0, 9, 27, 0, -324, -1215, 0, 18711, 75816, 0, -1301265, -5484996, 0, 100048689, 431943435, 0, -8192222064, -35942240565, 0, 700434986472, 3108770417700, 0, -61805774132388, -276711654879477, 0, 5586291123504300, 25180760594032407, 0, -514555201693265040

Offset

0,2

Links

Table of n, a(n) for n=0..30.

Index entries for reversions of series

Formula

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

a(n) = 9^n * binomial(2*n/3 - 4/3,n)/(n+1).

Prog

(PARI) a(n) = 9^n*binomial(2*n/3-4/3, n)/(n+1);

Crossrefs

Cf. A104624.

Sequence in context: A318303 A336710 A294106 * A375991 A094472 A347999

Adjacent sequences: A377265 A377266 A377267 * A377269 A377270 A377271

Keyword

sign,easy

Author

Seiichi Manyama, Oct 22 2024

Status

approved