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
KEYWORD
nonn,easy
AUTHOR
STATUS
approved