A020970 Expansion of 1/((1-7*x)*(1-9*x)*(1-10*x)).

1, 26, 453, 6610, 87221, 1079106, 12770773, 146348690, 1637020341, 17972357986, 194425446293, 2078548587570, 22007974284661, 231179027537666, 2412362060669013, 25033514235831250, 258557417951152181

Offset

0,2

Links

Table of n, a(n) for n=0..16.

Index entries for linear recurrences with constant coefficients, signature (26,-223,630).

Formula

G.f.: 1/((1-7*x)*(1-9*x)*(1-10*x)).

a(n) = 26*a(n-1) - 223*a(n-2) + 630*a(n-3), n>=3. - Vincenzo Librandi, Mar 15 2011

a(n) = 19*a(n-1) - 90*a(n-2) + 7^n, a(0)=1, a(1)=26. - Vincenzo Librandi, Mar 15 2011

a(n) = (7^(n+2)-3*9^(n+2)+2*10^(n+2))/6. - Bruno Berselli, Mar 15 2011

Mathematica

CoefficientList[Series[1/((1-7x)(1-9x)(1-10x)), {x, 0, 50}], x] (* G. C. Greubel, May 31 2018 *)

Prog

(PARI) x='x+O('x^30); Vec(1/((1-7*x)*(1-9*x)*(1-10*x))) \\ G. C. Greubel, May 31 2018
(Magma) m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-7*x)*(1-9*x)*(1-10*x))));  // G. C. Greubel, May 31 2018

Crossrefs

Sequence in context: A025996 A023540 A025979 * A023953 A020968 A025955

Adjacent sequences: A020967 A020968 A020969 * A020971 A020972 A020973

Keyword

nonn

Author

N. J. A. Sloane

Status

approved