OFFSET
0,2
LINKS
Clark Kimberling, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (2, 2, 2, -2, 0, -1)
FORMULA
G.f.: -((-1 - x + x^3)/(1 - 2 x - 2 x^2 - 2 x^3 + 2 x^4 + x^6)).
a(n) = 2*a(n-1) + 2*a(n-2) + 2*a(n-3) - 2*a(n-4) - a(n-6) for n >= 7.
MATHEMATICA
z = 60; s = x/(x - x^3); p = 1 - 2 s - 2 s^2;
Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A079978 *)
u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A291036 *)
u/2 (* A291037 *)
LinearRecurrence[{2, 2, 2, -2, 0, -1}, {1, 3, 8, 23, 66, 188}, 30] (* Harvey P. Dale, Sep 24 2017 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Sep 14 2017
STATUS
approved