A038865 (n+3)^3 - n^3.

63, 117, 189, 279, 387, 513, 657, 819, 999, 1197, 1413, 1647, 1899, 2169, 2457, 2763, 3087, 3429, 3789, 4167, 4563, 4977, 5409, 5859, 6327, 6813, 7317, 7839, 8379, 8937, 9513, 10107, 10719, 11349, 11997, 12663, 13347, 14049, 14769, 15507, 16263

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (3, -3, 1).

Formula

G.f.: -((9*(3*x^2-8*x+7))/(x-1)^3). - Harvey P. Dale, Mar 04 2014

a(1)=63, a(2)=117, a(3)=189, a(n)=3*a(n-1)-3*a(n-2)+a(n-3). - Harvey P. Dale, Mar 04 2014

Mathematica

Table[(n+3)^3-n^3, {n, 50}] (* or *) LinearRecurrence[{3, -3, 1}, {63, 117, 189}, 50] (* Harvey P. Dale, Mar 04 2014 *)

Prog

(PARI) a(n)=(n+3)^3-n^3 \\ Charles R Greathouse IV, Jun 17 2017

Crossrefs

Sequence in context: A166394 A038839 A038851 * A274460 A181556 A096023

Adjacent sequences: A038862 A038863 A038864 * A038866 A038867 A038868

Keyword

nonn,easy

Author

Jeff Burch

Status

approved