OFFSET
0,1
COMMENTS
Periodic with period length 9. - Ray Chandler, Apr 03 2017
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (0, 0, -1, 0, 0, -1).
FORMULA
G.f.: 1/(1 + x^3 + x^6). - Ilya Gutkovskiy, Aug 18 2017
a(n) = (19*m^8 - 628*m^7 + 8526*m^6 - 61152*m^5 + 247611*m^4 - 558012*m^3 + 637604*m^2 - 287408*m + 13440)/13440, where m = n mod 9. - Luce ETIENNE, Oct 18 2018
MAPLE
with(numtheory, cyclotomic); c := n->series(1/cyclotomic(n, x), x, 80);
MATHEMATICA
CoefficientList[Series[1/Cyclotomic[9, x], {x, 0, 100}], x] (* Vincenzo Librandi, Apr 03 2014 *)
LinearRecurrence[{0, 0, -1, 0, 0, -1}, {1, 0, 0, -1, 0, 0}, 81] (* Ray Chandler, Sep 15 2015 *)
PROG
(PARI) Vec(1/polcyclo(9)+O(x^99)) \\ Charles R Greathouse IV, Mar 24 2014
(Magma) &cat[[1, 0, 0, -1, 0, 0, 0, 0, 0]: n in [0..15]]; // Vincenzo Librandi, Apr 03 2014
CROSSREFS
KEYWORD
sign,easy
AUTHOR
STATUS
approved