OFFSET
0,4
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (0, 3, 0, -3).
FORMULA
a(n) = 3*a(n-2)-3*a(n-4) for n>5. G.f.: x^2*(1+2*x)*(1+x+x^2) / (1-3*x^2+3*x^4). [Colin Barker, Apr 04 2012]
MATHEMATICA
Join[{0, 0}, LinearRecurrence[{0, 3, 0, -3}, {1, 3, 6, 11}, 50]] (* Harvey P. Dale, Jan 14 2013 *)
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Paul Curtz, Sep 14 2007
EXTENSIONS
More terms from Colin Barker, Apr 04 2012
STATUS
approved