login
A015242
a(n) = (2*n - 7)*n^2.
1
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
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
KEYWORD
sign,easy
AUTHOR
N. J. A. Sloane, Dec 11 1999
STATUS
approved