A025993 Expansion of 1/((1-2x)(1-5x)(1-7x)(1-9x)).

1, 23, 344, 4258, 47487, 496725, 4981918, 48547136, 463544213, 4361492707, 40596873252, 374857310334, 3440520848779, 31434357529169, 286207079508746, 2598999610410652, 23553202070626785, 213115529239825311

Offset

0,2

Links

Table of n, a(n) for n=0..17.

Index entries for linear recurrences with constant coefficients, signature (23, -185, 601, -630).

Formula

a(n) = -8*2^n/105 +125*5^n/24 -343*7^n/20 +729*9^n/56. R. J. Mathar, Jun 20 2013

a(0)=1, a(1)=23, a(2)=344, a(3)=4258, a(n)=23*a(n-1)-185*a(n-2)+ 601*a(n-3)- 630*a(n-4). - Harvey P. Dale, Jul 04 2013

Mathematica

CoefficientList[Series[1/((1-2x)(1-5x)(1-7x)(1-9x)), {x, 0, 30}], x] (* or *) LinearRecurrence[{23, -185, 601, -630}, {1, 23, 344, 4258}, 30] (* Harvey P. Dale, Jul 04 2013 *)

Crossrefs

Sequence in context: A026324 A028039 A002118 * A111875 A028035 A077309

Adjacent sequences: A025990 A025991 A025992 * A025994 A025995 A025996

Keyword

nonn

Author

N. J. A. Sloane.

Status

approved