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A023772
Expansion of 1/((1-x)(1-5x)(1-9x)(1-12x)).
1
1, 27, 490, 7530, 105991, 1416477, 18318520, 231807060, 2890036381, 35658042927, 436707179350, 5319843165390, 64552636279171, 781063825879377, 9430663254710980, 113689073300930520, 1368959098545618361
OFFSET
0,2
FORMULA
a(n) = 27*a(n-1) - 239*a(n-2) + 753*a(n-3) - 540*a(n-4), with a(0)=1, a(1)=27, a(2)=490, a(3)=7530. [Harvey P. Dale, Mar 07 2012]
a(n) = (32*12^(n+3) - 77*9^(n+3) + 66*5^(n+3) -21)/7392. [Yahia Kahloune, Jun 27 2013]
MATHEMATICA
CoefficientList[Series[1/((1-x)(1-5x)(1-9x)(1-12x)), {x, 0, 30}], x] (* or *) LinearRecurrence[{27, -239, 753, -540}, {1, 27, 490, 7530}, 30] (* Harvey P. Dale, Mar 07 2012 *)
PROG
(Magma) m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)*(1-5*x)*(1-9*x)*(1-12*x)))); // Vincenzo Librandi, Jul 12 2013
CROSSREFS
Sequence in context: A042408 A023946 A020971 * A020726 A020969 A025956
KEYWORD
nonn,easy
AUTHOR
STATUS
approved