A133405 a(n) = 3*a(n-1) - a(n-3) + 3*a(n-4).

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

0,5

Links

Table of n, a(n) for n=0..30.

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

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

Mathematica

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

Crossrefs

Sequence in context: A027915 A295115 A114982 * A368088 A196952 A148921

Adjacent sequences: A133402 A133403 A133404 * A133406 A133407 A133408

Keyword

nonn

Author

Paul Curtz, Nov 24 2007

Status

approved