A015234 a(n) = (17 - 2*n)*n^2.

0, 15, 52, 99, 144, 175, 180, 147, 64, -81, -300, -605, -1008, -1521, -2156, -2925, -3840, -4913, -6156, -7581, -9200, -11025, -13068, -15341, -17856, -20625, -23660, -26973, -30576, -34481, -38700, -43245, -48128, -53361

Offset

0,2

Links

Ivan Panchenko, Table of n, a(n) for n = 0..1000

R. K. Hoeflin, Mega Test

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

Formula

G.f.: x*(15 - 8*x - 19*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*(15 + 11*x - 2*x^2)*exp(x). (End)

Mathematica

Table[(17 - 2*n)*n^2, {n, 0, 25}] (* or *) LinearRecurrence[{4, -6, 4, -1}, {0, 15, 52, 99}, 25] (* G. C. Greubel, Jul 30 2016 *)

Prog

(PARI) a(n)=(17-2*n)*n^2 \\ Charles R Greathouse IV, Jul 30 2016

Crossrefs

Sequence in context: A211563 A214522 A118238 * A295339 A346824 A193608

Adjacent sequences: A015231 A015232 A015233 * A015235 A015236 A015237

Keyword

sign,easy

Author

N. J. A. Sloane, Dec 11 1999

Status

approved