A128785 a(n) = n^2*6^n.

0, 6, 144, 1944, 20736, 194400, 1679616, 13716864, 107495424, 816293376, 6046617600, 43898443776, 313456656384, 2207257288704, 15359376162816, 105791621529600, 722204136308736, 4891804579528704, 32905425960566784

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (18,-108,216).

Formula

From R. J. Mathar, Jul 25 2009: (Start)

a(n) = 18*a(n-1) - 108*a(n-2) + 216*a(n-3).

G.f.: -6*x*(1+6*x)/(6*x-1)^3. (End)

Mathematica

Table[n^2 6^n, {n, 0, 30}] (* or *) LinearRecurrence[{18, -108, 216}, {0, 6, 144}, 30] (* Harvey P. Dale, Oct 03 2011 *)

Prog

(Magma) [n^2*6^n: n in [0..20]]; // Vincenzo Librandi, Oct 04 2011

Crossrefs

Cf. A036289; A007758.

Sequence in context: A037049 A196811 A200457 * A197178 A208230 A010043

Adjacent sequences: A128782 A128783 A128784 * A128786 A128787 A128788

Keyword

nonn,easy

Author

Mohammad K. Azarian, Apr 07 2007

Status

approved