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A022000
Expansion of 1/((1-x)(1-4x)(1-11x)(1-12x)).
1
1, 28, 533, 8648, 128889, 1824276, 24950461, 333078016, 4367420897, 56484732044, 722650676709, 9164986526904, 115404823162825, 1444532800672132, 17990818115880077, 223110488408176112
OFFSET
0,2
FORMULA
a(n) = (105*12^(n+3) - 132*11^(n+3) + 55*4^(n+3) - 28)/9240. [Yahia Kahloune, Jun 28 2013]
a(0)=1, a(1)=28, a(2)=533, a(3)=8648; for n>3, a(n) = 28*a(n-1) -251*a(n-2) +752*a(n-3) -528*a(n-4). - Vincenzo Librandi, Jul 12 2013
MATHEMATICA
CoefficientList[Series[1 / ((1 - x) (1 - 4 x) (1 - 11 x) (1 - 12 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 12 2013 *)
PROG
(Magma) I:=[1, 28, 533, 8648]; [n le 4 select I[n] else 28*Self(n-1)-251*Self(n-2)+752*Self(n-3)-528*Self(n-4): n in [1..25]]; /* or */ m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)*(1-4*x)*(1-11*x)*(1-12*x)))); // Vincenzo Librandi, Jul 12 2013
CROSSREFS
Sequence in context: A020972 A025957 A020758 * A020569 A163195 A092708
KEYWORD
nonn,easy
AUTHOR
STATUS
approved