A028028 Expansion of 1/((1-3*x)*(1-4*x)*(1-5*x)*(1-9*x)).

1, 21, 286, 3234, 33187, 322455, 3035152, 28040628, 256229413, 2326373049, 21042916258, 189930286182, 1712158289479, 15423616827003, 138884571944404, 1250325501927096, 11254768340210185, 101302177508279517

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (21, -155, 483, -540).

Formula

a(n) = (243/40)*9^n - (125/8)*5^n + (64/5)*4^n - (9/4)*3^n. - Neven Juric, Oct 22 2009

a(n) = 21*a(n-1) - 155*a(n-2) + 483*a(n-3) - 540*a(n-4); a(0)=1, a(1)=21, a(2)=286, a(3)=3234. - Harvey P. Dale, Aug 11 2011

Mathematica

CoefficientList[Series[1/((1-3x)(1-4x)(1-5x)(1-9x)), {x, 0, 30}], x] (* or *) LinearRecurrence[{21, -155, 483, -540}, {1, 21, 286, 3234}, 30] (* Harvey P. Dale, Aug 11 2011 *)

Prog

(Magma) [(243/40)*9^n - (125/8)*5^n + (64/5)*4^n - (9/4)*3^n: n in [0..20]]; // Vincenzo Librandi, Aug 12 2011
(PARI) Vec(1/((1-3*x)*(1-4*x)*(1-5*x)*(1-9*x))+O(x^99)) \\ Charles R Greathouse IV, Sep 27 2012

Crossrefs

Sequence in context: A025987 A125456 A296333 * A296633 A025971 A346844

Adjacent sequences: A028025 A028026 A028027 * A028029 A028030 A028031

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved