A020134 Ceiling of Gamma(n + 1/3)/Gamma(1/3).

1, 1, 1, 2, 4, 15, 80, 506, 3711, 30921, 288592, 2982110, 33797241, 416832634, 5557768441, 79661347642, 1221473997165, 19950741953682, 345812860530488, 6339902443058942, 122571447232472866, 2492286093726948269, 53168769999508229721, 1187435863322350463748

Offset

0,4

Links

Robert Israel, Table of n, a(n) for n = 0..450

Formula

a(n) ~ sqrt(3/(2*Pi))*Gamma(2/3)*(n/e)^n/n^(1/6). - Robert Israel, Dec 12 2018

Maple

Digits:= 64: f:= proc(n, x) ceil(GAMMA(n+x)/GAMMA(x)) end: seq(f(n, 1/3), n=0..25);

Mathematica

Array[Ceiling[Gamma[#+1/3]/Gamma[1/3]] &, 20, 0] (* Amiram Eldar, Dec 12 2018 *)

Crossrefs

Cf. A020044, A020089.

Sequence in context: A292757 A182449 A140836 * A307085 A228934 A120490

Adjacent sequences: A020131 A020132 A020133 * A020135 A020136 A020137

Keyword

nonn

Author

Simon Plouffe

Status

approved