A020984 Expansion of 1/((1-9*x)*(1-11*x)*(1-12*x)).

1, 32, 685, 12260, 198121, 2997512, 43322245, 605523020, 8251539841, 110243798192, 1449890883805, 18826690025780, 241910703467161, 3081364962170072, 38962058064701365, 489593051613776540, 6119501542765132081, 76138929852279201152, 943571277592721190925

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..920

Index entries for linear recurrences with constant coefficients, signature (32,-339,1188)

Formula

a(n) = 32*a(n-1) - 339*a(n-2) + 1188*a(n-3), n >= 3. - Vincenzo Librandi, Mar 18 2011

a(n) = 23*a(n-1) - 132*a(n-2) + 9^n, n >= 2. - Vincenzo Librandi, Mar 18 2011

a(n) = 4*12^(n+1) - 11^(n+2)/2+3*9^(n+1)/2. - R. J. Mathar, Mar 19 2011

Mathematica

CoefficientList[Series[1/((1-9*x)*(1-11*x)*(1-12*x)), {x, 0, 50}], x] (* G. C. Greubel, Feb 09 2018 *)

Prog

(PARI) x='x+O('x^30); Vec(1/((1-9*x)*(1-11*x)*(1-12*x))) \\ G. C. Greubel, Feb 09 2018
(Magma) R<x>:=PowerSeriesRing(Integers(), 30); Coefficients(R!(1/((1-9*x)*(1-11*x)*(1-12*x)))); // G. C. Greubel, Feb 09 2018

Crossrefs

Sequence in context: A240362 A025031 A025008 * A247997 A199708 A264093

Adjacent sequences: A020981 A020982 A020983 * A020985 A020986 A020987

Keyword

nonn

Author

N. J. A. Sloane

Extensions

a(18) corrected by Andrew Howroyd, Feb 23 2018

Status

approved