A020973 Expansion of 1/((1-7*x)*(1-10*x)*(1-11*x)).

1, 28, 527, 8330, 119361, 1607088, 20736787, 259516390, 3174562421, 38159361548, 452427201447, 5305418786850, 61660643651881, 711374339146408, 8156868543440507, 93047809667655710, 1056781696172883741

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..955

Index entries for linear recurrences with constant coefficients, signature (28,-257,770).

Formula

a(n) = 28*a(n-1) - 257*a(n-2) + 770*a(n-3) for n>=3. - Vincenzo Librandi, Mar 15 2011

a(n) = 21*a(n-1) - 110*a(n-2) + 7^n for n>1, a(0)=1, a(1)=28. - Vincenzo Librandi, Mar 15 2011

a(n) = (3*11^(n+2) - 4*10^(n+2) + 7^(n+2))/12. - Yahia Kahloune, Jun 30 2013

Mathematica

CoefficientList[Series[1/((1-7x)(1-10x)(1-11x)), {x, 0, 50}], x] (* G. C. Greubel, May 31 2018 *)

Prog

(PARI) x='x+O('x^30); Vec(1/((1-7*x)*(1-10*x)*(1-11*x))) \\ G. C. Greubel, May 31 2018
(Magma) m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-7*x)*(1-10*x)*(1-11*x)))); // G. C. Greubel, May 31 2018

Crossrefs

Sequence in context: A024347 A025984 A020977 * A023947 A020972 A025957

Adjacent sequences: A020970 A020971 A020972 * A020974 A020975 A020976

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved