OFFSET
0,5
COMMENTS
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (0,0,3,0,0,-3,0,0,1).
FORMULA
G.f.: (x*(1+x)/(1-x^3))^3.
MATHEMATICA
LinearRecurrence[{0, 0, 3, 0, 0, -3, 0, 0, 1}, {0, 0, 0, 1, 3, 3, 4, 9, 9}, 50] (* Harvey P. Dale, Jan 23 2013 *)
PROG
(PARI) x='x+O('x^50); concat([0, 0, 0], Vec((x*(1+x)/(1-x^3))^3)) \\ G. C. Greubel, Jun 29 2017
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Philippe Deléham, Jan 21 2012
STATUS
approved