A024026 a(n) = 3^n - n^3.

1, 2, 1, 0, 17, 118, 513, 1844, 6049, 18954, 58049, 175816, 529713, 1592126, 4780225, 14345532, 43042625, 129135250, 387414657, 1162254608, 3486776401, 10460343942, 31381048961, 94143166660, 282429522657, 847288593818

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Formula

G.f.: (-1 + 5*x - 5*x^2 - 7*x^3 - 4*x^4)/((3*x-1)*(x-1)^4). - Maksym Voznyy (voznyy(AT)mail.ru), Aug 14 2009

Maple

seq(3^n-n^3, n=0..25); # Zerinvary Lajos, Jul 01 2007

Mathematica

lst={}; Do[AppendTo[lst, (3^n-n^3)], {n, 0, 5!}]; lst (* Vladimir Joseph Stephan Orlovsky, Jan 15 2009 *)

Prog

(Magma) [3^n-n^3: n in [0..30]]; // Vincenzo Librandi, May 14 2011
(PARI) a(n)=3^n-n^3 \\ Charles R Greathouse IV, Jul 02 2013

Crossrefs

Sequence in context: A361718 A355565 A202700 * A355006 A269946 A009829

Adjacent sequences: A024023 A024024 A024025 * A024027 A024028 A024029

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved