OFFSET
0,3
COMMENTS
LINKS
Index entries for linear recurrences with constant coefficients, signature (2,3,6,-1,0,-1).
FORMULA
G.f.: (1 - x - 3*x^2 - x^3) / ((1 - 3*x - x^2 - x^3)*(1 + x + x^2 - x^3)).
EXAMPLE
PROG
(PARI) {a(n)=polcoeff((1-x-3*x^2-x^3)/((1-3*x-x^2-x^3)*(1+x+x^2-x^3)+x*O(x^n)), n)}
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul D. Hanna, Nov 19 2011
STATUS
approved