A061263 a(n) = floor(n^3/9).

0, 0, 0, 3, 7, 13, 24, 38, 56, 81, 111, 147, 192, 244, 304, 375, 455, 545, 648, 762, 888, 1029, 1183, 1351, 1536, 1736, 1952, 2187, 2439, 2709, 3000, 3310, 3640, 3993, 4367, 4763, 5184, 5628, 6096, 6591, 7111, 7657, 8232, 8834, 9464, 10125, 10815, 11535

Offset: 0

Author

Henry Bottomley, Apr 24 2001

Keywords

• easy
• nonn

Examples

			a(4) = floor(4^3 / 9) = floor(64/9) = 7.
		

Links

• Harry J. Smith, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (3,-3,2,-3,3,-1).

Crossrefs

Cf. A061105.

Programs

PARI

a(n) = { n^3\9 } \\ Harry J. Smith, Jul 20 2009

Formula

G.f.: x^3*(3-2*x+x^2) / ( (1+x+x^2)*(x-1)^4 ). - R. J. Mathar, Feb 20 2011