A377242 Expansion of 1/(1 - 9*x*(1 + 9*x)^(1/3))^(1/3).

1, 3, 27, 207, 2052, 18549, 188487, 1822257, 18757170, 187833654, 1950543018, 19946428524, 208533115953, 2161631202408, 22722158457018, 237747753079992, 2510341213633218, 26444343663932265, 280274270573324547, 2967476856390453393, 31551693369673358214

Offset

0,2

Links

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

Formula

a(n) = (-9)^n * Sum_{k=0..n} binomial(-1/3,k) * binomial(n-4*k/3-1,n-k).

Prog

(PARI) a(n) = (-9)^n*sum(k=0, n, binomial(-1/3, k)*binomial(n-4*k/3-1, n-k));

Crossrefs

Cf. A377241.

Sequence in context: A043023 A198686 A357662 * A087426 A145608 A083713

Adjacent sequences: A377239 A377240 A377241 * A377243 A377244 A377245

Keyword

nonn

Author

Seiichi Manyama, Oct 21 2024

Status

approved