OFFSET
0,3
LINKS
Index entries for linear recurrences with constant coefficients, signature (1, 1, 2, -2, -2, -1, 1, 1).
FORMULA
a(n) = a(n-1)+2*a(n-2)-2*a(n-3)-2*a(n-4)-a(n-5)+a(n-6)+a(n-7).
G.f.: 1/((1 - x - x^2)*(1 - x^3)^2).
MATHEMATICA
f[x_] := (1 - x^3)^2; g[x] := 1 - x - x^2;
s = Normal[Series[1/(f[x] g[x]), {x, 0, 60}]]
c = CoefficientList[s, x] (* A213044 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jun 10 2012
STATUS
approved