A133405 a(n) = 3*a(n-1) - a(n-3) + 3*a(n-4), with initial values 0,0,0,1.

0, 0, 0, 1, 3, 9, 26, 78, 234, 703, 2109, 6327, 18980, 56940, 170820, 512461, 1537383, 4612149, 13836446, 41509338, 124528014, 373584043, 1120752129, 3362256387, 10086769160, 30260307480, 90780922440, 272342767321, 817028301963, 2451084905889, 7353254717666

Offset: 0

Author

Paul Curtz, Nov 24 2007

Keywords

• nonn

Links

• Index entries for linear recurrences with constant coefficients, signature (3,0,-1,3).

Programs

Mathematica

LinearRecurrence[{3, 0, -1, 3}, {0, 0, 0, 1}, 60] (* Vladimir Joseph Stephan Orlovsky, Jun 20 2011 *)

Formula

O.g.f.: -x^3/((3*x-1)*(x+1)*(x^2-x+1)) = -(1/28)/(3*x-1)-(1/12)/(x+1)+(1/21)*(-5*x+1)/(x^2-x+1). - R. J. Mathar, Nov 28 2007