Cyclotomic
Cyclotomic[n, x] gives the nth cyclotomic polynomial in x.
Examples
First few cyclotomic polynomials:
Cyclotomic[1, x]
(* x - 1 *)
Cyclotomic[2, x]
(* x + 1 *)
Cyclotomic[6, x]
(* x^2 - x + 1 *)Please visit the official Wolfram Language Reference for more details.