A026028 Expansion of 1/((1-2x)(1-5x)(1-9x)(1-11x)).

1, 27, 480, 7130, 96111, 1221537, 14941750, 178032960, 2082076821, 24019528247, 274281235020, 3107772782790, 35002020287131, 392372934746157, 4382268859012290, 48800507502984620, 542165787330583041

Offset

0,2

Links

Table of n, a(n) for n=0..16.

Index entries for linear recurrences with constant coefficients, signature (27,-249,893,-990).

Formula

G.f.: 1/((1-2*x)*(1-5*x)*(1-9*x)*(1-11*x)).

a(n) = -8*2^n/189 +125*5^n/72 -729*9^n/56 +1331*11^n/108. R. J. Mathar, Jun 22 2013

a(n) = 27*a(n-1)-249*a(n-2)+893*a(n-3)-990*a(n-4). - Wesley Ivan Hurt, Sep 04 2022

Mathematica

CoefficientList[Series[1/((1-2x)(1-5x)(1-9x)(1-11x)), {x, 0, 30}], x] (* or *) LinearRecurrence[{27, -249, 893, -990}, {1, 27, 480, 7130}, 30] (* Harvey P. Dale, Aug 14 2018 *)

Crossrefs

Sequence in context: A028048 A028063 A024441 * A026543 A028046 A109821

Adjacent sequences: A026025 A026026 A026027 * A026029 A026030 A026031

Keyword

nonn

Author

N. J. A. Sloane.

Status

approved