A015242 a(n) = (2*n - 7)*n^2.

0, -5, -12, -9, 16, 75, 180, 343, 576, 891, 1300, 1815, 2448, 3211, 4116, 5175, 6400, 7803, 9396, 11191, 13200, 15435, 17908, 20631, 23616, 26875, 30420, 34263, 38416, 42891, 47700, 52855, 58368, 64251

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..10000

Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).

Formula

G.f.: x*(-5 + 8*x + 9*x^2) / (x-1)^4. - R. J. Mathar, Oct 25 2011

From G. C. Greubel, Jul 30 2016: (Start)

a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4).

E.g.f.: x*(-5 - x + 2*x^2)*exp(x). (End)

Mathematica

Table[(2*n - 7)*n^2, {n, 0, 25}] (* or *) LinearRecurrence[{4, -6, 4, -1}, {0, -5, -12, -9}, 25] (* G. C. Greubel, Jul 30 2016 *)

Prog

(Magma) [(2*n-7)*n^2: n in [0..40]]; // Vincenzo Librandi, Oct 26 2011
(PARI) a(n)=(2*n-7)*n^2 \\ Charles R Greathouse IV, Jul 30 2016

Crossrefs

Sequence in context: A169729 A070368 A066326 * A009415 A251935 A195031

Adjacent sequences: A015239 A015240 A015241 * A015243 A015244 A015245

Keyword

sign,easy

Author

N. J. A. Sloane, Dec 11 1999

Status

approved