A023954 Expansion of g.f. 1/((1-x)*(1-6*x)*(1-8*x)*(1-9*x)).

1, 24, 379, 4974, 58825, 651228, 6891463, 70602378, 706070629, 6931922712, 67078160227, 641665645062, 6081300568513, 57197856053076, 534603948966271, 4970585718586626, 46011858222290077, 424339730032027920, 3901043490487591195, 35766010007671052670, 327151426205429404921

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,-197,606,-432).

Formula

a(n) = (35*9^(n+3) - 60*8^(n+3) + 28*6^(n+3) - 3)/840. - Yahia Kahloune, Jun 29 2013

a(n) = 24*a(n-1)-197*a(n-2)+606*a(n-3)-432*a(n-4). - Vincenzo Librandi, Jul 16 2013

Mathematica

CoefficientList[Series[1 / ((1 - x) (1 - 6 x) (1 - 8 x) (1 - 9 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 16 2013 *)

Prog

(Magma) m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)*(1-6*x)*(1-8*x)*(1-9*x)))); // Vincenzo Librandi, Jul 16 2013
(Magma) I:=[1, 24, 379, 4974]; [n le 4 select I[n] else 24*Self(n-1)-197*Self(n-2)+606*Self(n-3)-432*Self(n-4): n in [1..25]]; // Vincenzo Librandi, Jul 16 2013

Crossrefs

Sequence in context: A028040 A025994 A004335 * A028036 A025977 A023951

Adjacent sequences: A023951 A023952 A023953 * A023955 A023956 A023957

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved