A020980 Expansion of 1/((1-8*x)*(1-10*x)*(1-12*x)).

1, 30, 604, 10200, 156016, 2241120, 30844864, 411749760, 5373888256, 68949788160, 873102490624, 10942870149120, 136039563882496, 1680275743334400, 20645716733968384, 252607863319265280

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Index entries for linear recurrences with constant coefficients, signature (30,-296,960).

Formula

a(n) = (12^(n+2) - 2*10^(n+2) + 8^(n+2))/8. - Yahia Kahloune, Jun 30 2013

a(0)=1, a(1)=30, a(2)=604; for n>2, a(n) = 30*a(n-1) -296*a(n-2) +960*a(n-3). - Vincenzo Librandi, Jul 05 2013

a(n) = 22*a(n-1) -120*a(n-2) +8^n. - Vincenzo Librandi, Jul 05 2013

Mathematica

CoefficientList[Series[1 / ((1 - 8 x) (1 - 10 x) (1 - 12 x)), {x, 0, 20}], x]  (* Harvey P. Dale, Mar 23 2011 *)

Prog

(Magma) m:=20; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-8*x)*(1-10*x)*(1-12*x)))); /* or */ I:=[1, 30, 604]; [n le 3 select I[n] else 30*Self(n-1)-296*Self(n-2)+960*Self(n-3): n in [1..20]]; // Vincenzo Librandi, Jul 05 2013
(PARI) x='x+O('x^30); Vec(1/((1-8*x)*(1-10*x)*(1-12*x))) \\ G. C. Greubel, Feb 09 2018

Crossrefs

Sequence in context: A020982 A024436 A042744 * A051303 A020975 A277877

Adjacent sequences: A020977 A020978 A020979 * A020981 A020982 A020983

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved