OFFSET
0,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (3, 0, -4, 2).
FORMULA
a(0)=1, a(1)=3, a(2)=9, a(3)=23, a(n)=3*a(n-1)-4*a(n-3)+2*a(n-4). - Harvey P. Dale, Apr 02 2013
MATHEMATICA
CoefficientList[Series[(1-x)^(-1)/(1-2x-2x^2+2x^3), {x, 0, 40}], x] (* or *) LinearRecurrence[{3, 0, -4, 2}, {1, 3, 9, 23}, 40] (* Harvey P. Dale, Apr 02 2013 *)
PROG
(PARI) Vec((1-x)^(-1)/(1-2*x-2*x^2+2*x^3)+O(x^99)) \\ Charles R Greathouse IV, Sep 26 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Nov 17 2002
STATUS
approved