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A024346 Expansion of 1/((1-x)(1-6x)(1-9x)(1-11x)). 1
1, 27, 484, 7266, 98959, 1269177, 15642586, 187539120, 2204181925, 25529358855, 292445725936, 3321943348542, 37489352241979, 420930326166741, 4707254688375814, 52473555698990412, 583456285162491601 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Index entries for linear recurrences with constant coefficients, signature (27,-245,813,-594).

FORMULA

a(0)=1, a(1)=27, a(2)=484, a(3)=7266; for n>3 a(n) = 27*a(n-1) -245*a(n-2) +813*a(n-3) -594*a(n-4). - Vincenzo Librandi, Jul 16 2013

a(n) = (12*11^(n+3) - 25*9^(n+3) + 16*6^(n+3) - 3)/1200. [Yahia Kahloune, Aug 13 2013]

MATHEMATICA

CoefficientList[Series[1 / ((1 - x) (1 - 6 x) (1 - 9 x) (1 - 11 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 16 2013 *)

LinearRecurrence[{27, -245, 813, -594}, {1, 27, 484, 7266}, 20] (* Harvey P. Dale, Oct 13 2016 *)

PROG

(MAGMA) m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)*(1-6*x)*(1-9*x)*(1-11*x)))); /* or */ I:=[1, 27, 484, 7266]; [n le 4 select I[n] else 27*Self(n-1)-245*Self(n-2)+813*Self(n-3)-594*Self(n-4): n in [1..25]]; // Vincenzo Librandi, Jul 16 2013

(PARI) a(n) = (12*11^(n+3) - 25*9^(n+3) + 16*6^(n+3) - 3)/1200; \\ Joerg Arndt, Aug 13 2013

CROSSREFS

Sequence in context: A057494 A024439 A026006 * A025983 A081139 A020976

Adjacent sequences:  A024343 A024344 A024345 * A024347 A024348 A024349

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified April 2 17:30 EDT 2020. Contains 333188 sequences. (Running on oeis4.)