%I #13 Jul 24 2017 13:01:23
%S 1,0,1,0,0,0,-1,0,-1,0,-1,0,0,0,0,0,0,0,0,0,1,0,1,0,1,0,0,0,0,0,0,0,0,
%T 0,-1,0,-1,0,-1,0,0,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%U 0,0,0,0,1,0,1,0,0,0,-1,0,-1,0,-1
%N Inverse of 420th cyclotomic polynomial.
%C Periodic with period length 420. - _Ray Chandler_, Apr 04 2017
%H Ray Chandler, <a href="/A014429/b014429.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec#order_96">Index entries for linear recurrences with constant coefficients</a>, signature (0, 1, 0, -1, 0, 0, 0, 0, 0, -1, 0, 1, 0, -2, 0, 1, 0, -1, 0, 0, 0, 0, 0, -1, 0, 1, 0, -1, 0, 1, 0, -1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, -1, 0, 1, 0, -1, 0, 1, 0, -1, 0, 0, 0, 0, 0, -1, 0, 1, 0, -2, 0, 1, 0, -1, 0, 0, 0, 0, 0, -1, 0, 1, 0, -1).
%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[420,x],{x,0,120}],x] (* _Harvey P. Dale_, Jul 24 2017 *)
%K sign
%O 0,1
%A _Simon Plouffe_