A025929 Expansion of 1/((1-2x)(1-3x)(1-4x)(1-12x)).

1, 21, 307, 3969, 48979, 593817, 7152139, 85937313, 1031713507, 12382483113, 148597656571, 1783203843057, 21398575559635, 256783429254009, 3081403255517803, 36976847527073601, 443722204297332163

Offset

0,2

Links

Harvey P. Dale, Table of n, a(n) for n = 0..900

Index entries for linear recurrences with constant coefficients, signature (21,-134,336,-288)

Formula

From Vincenzo Librandi, Mar 19 2011: (Start)

a(n) = 21*a(n-1) - 134*a(n-2) + 336*a(n-3) - 288*a(n-4), n >= 4.

a(n) = 16*a(n-1) - 48*a(n-2) + 3^(n+1) - 2^(n+1), n >= 2. (End)

a(n) = 3^(n+1) - 2^(n+1)/5 - 2^(2*n+2) + 12^(n+1)/5. - R. J. Mathar, Mar 19 2011

Mathematica

CoefficientList[Series[1/((1-2x)(1-3x)(1-4x)(1-12x)), {x, 0, 30}], x] (* or *) LinearRecurrence[{21, -134, 336, -288}, {1, 21, 307, 3969}, 30] (* Harvey P. Dale, May 18 2012 *)

Prog

(PARI) Vec(1/((1-2*x)*(1-3*x)*(1-4*x)*(1-12*x))+O(x^99)) \\ Charles R Greathouse IV, Sep 27 2012

Crossrefs

Sequence in context: A021268 A018069 A019488 * A021244 A183463 A125478

Adjacent sequences: A025926 A025927 A025928 * A025930 A025931 A025932

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved