A015230 - OEIS

%I #16 Apr 07 2017 12:16:00

%S 1,-1,0,1,-1,0,1,-1,0,1,-1,1,0,-1,1,0,-1,1,0,-1,1,0,0,0,0,0,0,0,0,0,0,

%T 0,0,0,0,0,0,1,-1,0,1,-1,0,1,-1,0,1,-1,1,0,-1,1,0,-1,1,0,-1,1,0,0,0,0,

%U 0,0,0,0,0,0,0,0,0,0,0,0,1,-1,0,1,-1,0,1

%N Inverse of 1221st cyclotomic polynomial.

%C Periodic with period length 1221. - _Ray Chandler_, Apr 07 2017

%H Ray Chandler, <a href="/A015230/b015230.txt">Table of n, a(n) for n = 0..2000</a>

%H <a href="/index/Rec#order_720">Index entries for linear recurrences with constant coefficients</a>, order 720.

%H <a href="/index/Pol#poly_cyclo_inv">Index to sequences related to inverse of cyclotomic polynomials</a>

%p with(numtheory,cyclotomic); c := n->series(1/cyclotomic(n,x),x,80);

%t CoefficientList[Series[1/Cyclotomic[1221,x],{x,0,100}],x] (* _Harvey P. Dale_, Apr 12 2016 *)

%K sign

%O 0,1

%A _Simon Plouffe_