A373818 Expansion of 1/(2 - 1/(1 - 9*x)^(1/3)).

1, 3, 27, 261, 2592, 26082, 264384, 2691954, 27488403, 281236779, 2881239093, 29546332821, 303201787140, 3113043334560, 31974807932820, 328518361498968, 3376062893960244, 34700713221307482, 356719230542209212, 3667432457788644762, 37708163269636391982

Offset

0,2

Links

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

Formula

a(n) = 9^n * Sum_{k>=0} (1/2)^(k+1) * binomial(n-1+k/3,n).

Prog

(PARI) my(N=30, x='x+O('x^N)); Vec(1/(2-1/(1-9*x)^(1/3)))

Crossrefs

Cf. A001027, A373939.

Sequence in context: A361895 A279658 A370620 * A026294 A199688 A275998

Adjacent sequences: A373815 A373816 A373817 * A373819 A373820 A373821

Keyword

nonn,easy

Author

Seiichi Manyama, Aug 04 2024

Status

approved