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A020571 Expansion of 1/((1-6x)(1-7x)(1-9x)). 1
1, 22, 325, 4030, 45301, 478702, 4851925, 47752510, 460048501, 4362445582, 40876539925, 379553364190, 3499808594101, 32098136255662, 293160602826325, 2668857246099070, 24235419069434101, 219645625266148942 (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 (22,-159,378).

FORMULA

a(n) = 12*6^n -49*7^n/2 +27*9^n/2. - R. J. Mathar, Jun 30 2013

a(0)=1, a(1)=22, a(2)=325; for n>2, a(n) = 22*a(n-1) -159*a(n-2) +378*a(n-3). - Vincenzo Librandi, Jul 04 2013

a(n) = 16*a(n-1) -63*a(n-2) +6^n. - Vincenzo Librandi, Jul 04 2013

MATHEMATICA

CoefficientList[Series[1 / ((1 - 6 x) (1 - 7 x) (1 - 9 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 04 2013 *)

LinearRecurrence[{22, -159, 378}, {1, 22, 325}, 30] (* Harvey P. Dale, Dec 11 2018 *)

PROG

(MAGMA) m:=20; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-6*x)*(1-7*x)*(1-9*x)))); /* or */ I:=[1, 22, 325]; [n le 3 select I[n] else 22*Self(n-1)-159*Self(n-2)+378*Self(n-3): n in [1..20]]; // Vincenzo Librandi, Jul 04 2013

CROSSREFS

Sequence in context: A022343 A025945 A288576 * A021874 A025963 A020343

Adjacent sequences:  A020568 A020569 A020570 * A020572 A020573 A020574

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified April 1 10:33 EDT 2020. Contains 333159 sequences. (Running on oeis4.)