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A020567 Expansion of 1/((1-5x)(1-10x)(1-11x)). 1
1, 26, 461, 6946, 95781, 1250466, 15739501, 193056386, 2323229621, 27553572706, 323079534141, 3753826047426, 43291842381061, 496209045488546, 5658293396858381, 64241196847864066, 726653012738614101 (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 (26,-215,550).

FORMULA

a(n) = 5*5^n/6 -20*10^n +121*11^n/6. - R. J. Mathar, Jun 30 2013

a(0)=1, a(1)=26, a(2)=461; for n>2, a(n) = 26*a(n-1) -215*a(n-2) +550*a(n-3). - Vincenzo Librandi, Jul 04 2013

a(n) = 21*a(n-1) -110*a(n-2) +5^n. - Vincenzo Librandi, Jul 04 2013

MATHEMATICA

CoefficientList[Series[1 / ((1 - 5 x) (1 - 10 x) (1 - 11 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 04 2013 *)

PROG

(MAGMA) m:=20; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-5*x)*(1-10*x)*(1-11*x)))); /* or */ I:=[1, 26, 461]; [n le 3 select I[n] else 26*Self(n-1)-215*Self(n-2)+550*Self(n-3): n in [1..20]]; // Vincenzo Librandi, Jul 04 2013

CROSSREFS

Sequence in context: A158434 A158438 A158426 * A158427 A158428 A158425

Adjacent sequences:  A020564 A020565 A020566 * A020568 A020569 A020570

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified October 17 10:04 EDT 2019. Contains 328107 sequences. (Running on oeis4.)