A016322 Expansion of 1/((1-2x)(1-9x)(1-11x)).

1, 22, 345, 4730, 60461, 740982, 8834065, 103324210, 1191912021, 13609144142, 154183593785, 1736366607690, 19463156373181, 217362833310502, 2420404185281505, 26889163207923170, 298163249815659941

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..900

Index entries for linear recurrences with constant coefficients, signature (22,-139,198).

Formula

From Vincenzo Librandi, Oct 09 2011: (Start)

a(n) = (7*11^(n+2) + 2^(n+3) - 9^(n+3))/126.

a(n) = 20*a(n-1) - 99*a(n-2) + 2^n.

a(n) = 22*a(n-1) - 139*a(n-2) + 198*a(n-3), n >= 3. (End)

Mathematica

CoefficientList[Series[1/((1-2x)(1-9x)(1-11x)), {x, 0, 30}], x] (* or *) LinearRecurrence[{22, -139, 198}, {1, 22, 345}, 30] (* Harvey P. Dale, Oct 15 2019 *)

Prog

(Magma) [(7*11^(n+2) +2^(n+3)-9^(n+3))/126 : n in [0..20]]; // Vincenzo Librandi, Oct 09 2011
(PARI) Vec(1/((1-2*x)*(1-9*x)*(1-11*x))+O(x^99)) \\ Charles R Greathouse IV, Sep 26 2012

Crossrefs

Sequence in context: A277835 A018055 A277834 * A096047 A016320 A103722

Adjacent sequences: A016319 A016320 A016321 * A016323 A016324 A016325

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved