OFFSET
0,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (2,0,0,1,-2).
FORMULA
G.f.: A(x) = (1 - 2*x^2 - 5*x^4)/(1-x^4)/(1-2*x).
MATHEMATICA
CoefficientList[Series[(1-2x^2-5x^4)/(1-x^4)/(1-2x), {x, 0, 40}], x] (* or *) LinearRecurrence[{2, 0, 0, 1, -2}, {1, 2, 2, 4, 4}, 40] (* Harvey P. Dale, Jul 29 2021 *)
PROG
(PARI) {a(n)=polcoeff((1 - 2*x^2 - 5*x^4)/(1-x^4)/(1-2*x+x*O(x^n)), n, x)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Apr 27 2006
STATUS
approved