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A015240
a(n) = (2*n - 5)n^2.
2
0, -3, -4, 9, 48, 125, 252, 441, 704, 1053, 1500, 2057, 2736, 3549, 4508, 5625, 6912, 8381, 10044, 11913, 14000, 16317, 18876, 21689, 24768, 28125, 31772, 35721, 39984, 44573, 49500, 54777, 60416, 66429
OFFSET
0,2
FORMULA
G.f.: x*(-3 + 8*x + 7*x^2)/(1-x)^4. - Ivan Panchenko, Nov 09 2013
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*(-3 + x + 2*x^2)*exp(x). (End)
MATHEMATICA
Table[(2*n - 5)n^2, {n, 0, 25}] (* or *) LinearRecurrence[{4, -6, 4, -1}, {0, -3, -4, 9}, 25] (* G. C. Greubel, Jul 30 2016 *)
PROG
(PARI) a(n)=(2*n-5)*n^2 \\ Charles R Greathouse IV, Jul 30 2016
CROSSREFS
Sequence in context: A084715 A225467 A225473 * A032477 A073015 A364376
KEYWORD
sign,easy
AUTHOR
N. J. A. Sloane, Dec 11 1999
STATUS
approved