A178489 a(n) = floor(n^(1/6)): integer part of sixth root of n.

0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2

Offset: 0

Author

M. F. Hasler, Oct 09 2010

Keywords

• easy
• nonn

Crossrefs

Cf. A000196, A048766, A178487.

Programs

Mathematica

Floor[Power[Range[0,110], (6)^-1]] (* Harvey P. Dale, Jul 18 2011 *)

PARI

A178489(n)=floor(sqrtn(n+.5,6))

PARI

a(n) = sqrtnint(n, 6); \\ Michel Marcus, Dec 22 2016

Formula

G.f.: Sum_{k>=1} x^(k^6)/(1 - x). - Ilya Gutkovskiy, Dec 22 2016