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A020579 Expansion of 1/((1-6x)(1-8x)(1-9x)). 1
1, 23, 355, 4595, 53851, 592403, 6240235, 63710915, 635468251, 6225852083, 60146237515, 574587484835, 5439634923451, 51116555484563, 477406092913195, 4435981769620355, 41041272503703451, 378327871809737843 (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 (23,-174,432).

FORMULA

a(n) = 6*6^n -32*8^n +27*9^n. - R. J. Mathar, Jun 30 2013

a(0)=1, a(1)=23, a(2)=355; for n>2, a(n) = 23*a(n-1) -174*a(n-2) +432*a(n-3). - Vincenzo Librandi, Jul 04 2013

a(n) = 17*a(n-1) -72*a(n-2) +6^n. - Vincenzo Librandi, Jul 04 2013

MATHEMATICA

CoefficientList[Series[1 / ((1 - 6 x) (1 - 8 x) (1 - 9 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 04 2013 *)

PROG

(Magma) m:=20; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-6*x)*(1-8*x)*(1-9*x)))); /* or */ I:=[1, 23, 355]; [n le 3 select I[n] else 23*Self(n-1)-174*Self(n-2)+432*Self(n-3): n in [1..20]]; // Vincenzo Librandi, Jul 04 2013

CROSSREFS

Sequence in context: A142617 A025949 A025969 * A021914 A022412 A025946

Adjacent sequences: A020576 A020577 A020578 * A020580 A020581 A020582

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified November 28 03:39 EST 2022. Contains 358406 sequences. (Running on oeis4.)