A021304 Expansion of 1/((1-x)(1-2x)(1-9x)(1-12x)).

1, 24, 403, 5886, 80113, 1046748, 13329631, 166873722, 2064748525, 25337358072, 309091680859, 3754490630358, 45462401712937, 549225447909396, 6623795021132887, 79783347069641394, 960080426180248549

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,-173,366,-216).

Formula

a(n) = (28*12^(n+3) - 55*9^(n+3) + 132*2^(n+3) - 105)/9240. - Yahia Kahloune, Jul 07 2013

a(0)=1, a(1)=24, a(2)=403, a(3)=5886; for n>3, a(n) = 24*a(n-1) -173*a(n-2) +366*a(n-3) -216*a(n-4). - Vincenzo Librandi, Jul 09 2013

a(0)=1, a(1)=24; for n>1, a(n) = 21*a(n-1) -108*a(n-2) +2^n -1. - Vincenzo Librandi, Jul 09 2013

Mathematica

CoefficientList[Series[1 / ((1 - x) (1 - 2 x) (1 - 9 x) (1 -12 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 09 2013 *)

Prog

(Magma) I:=[1, 24, 403, 5886]; [n le 4 select I[n] else 24*Self(n-1)-173*Self(n-2)+366*Self(n-3)-216*Self(n-4): n in [1..25]]; // Vincenzo Librandi, Jul 09 2013
(Magma) m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)*(1-2*x)*(1-9*x)*(1-12*x)))); // Vincenzo Librandi, Jul 09 2013

Crossrefs

Sequence in context: A019677 A021314 A018206 * A018092 A331931 A227750

Adjacent sequences: A021301 A021302 A021303 * A021305 A021306 A021307

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved