A362157 Expansion of -1/(1 - x * (1-9*x)^(1/3)).

-1, -1, 2, 14, 62, 317, 1967, 13544, 98012, 731273, 5581682, 43377617, 342035204, 2729286017, 21996002729, 178769985791, 1463465010995, 12055667829734, 99858109234379, 831150925169516, 6947819513136614, 58303331305857293, 490961900646977570

Offset: 0

Author

Seiichi Manyama, Apr 09 2023

Keywords

• sign
• easy

Crossrefs

Cf. A004987, A362156.

Programs

PARI

my(N=30, x='x+O('x^N)); Vec(-1/(1-x*(1-9*x)^(1/3)))

Formula

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