A020584 Expansion of 1/((1-6x)(1-8x)(1-10x)).

1, 24, 388, 5280, 65296, 760704, 8515648, 92705280, 989122816, 10397865984, 108092228608, 1114193633280, 11410283892736, 116262680100864, 1179983894560768, 11939165879009280, 120509095367213056

Offset

0,2

Links

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

Index entries for linear recurrences with constant coefficients, signature (24,-188,480).

Formula

a(n) = 9*6^n/2 -16*8^n +25*10^n/2. - R. J. Mathar, Jun 30 2013

a(0)=1, a(1)=24, a(2)=388; for n>2, a(n) = 24*a(n-1) -188*a(n-2) +480*a(n-3). - Vincenzo Librandi, Jul 04 2013

a(n) = 18*a(n-1) -80*a(n-2) +6^n. - Vincenzo Librandi, Jul 04 2013

Mathematica

CoefficientList[Series[1 / ((1 - 6 x) (1 - 8 x) (1 - 10 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 04 2013 *)

Prog

(Magma) m:=20; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-6*x)*(1-8*x)*(1-10*x)))); /* or */ I:=[1, 24, 388]; [n le 3 select I[n] else 24*Self(n-1)-188*Self(n-2)+480*Self(n-3): n in [1..20]]; // Vincenzo Librandi, Jul 04 2013

Crossrefs

Sequence in context: A022455 A021954 A025950 * A025970 A021924 A020494

Adjacent sequences: A020581 A020582 A020583 * A020585 A020586 A020587

Keyword

nonn,easy

Author

N. J. A. Sloane.

Status

approved