“…x − e 2πi k n For example, we have Φ 15 (x) = 1 − x + x 3 − x 4 + x 5 − x 7 + x 8 Ψ 15 (x) = −1 − x − x 2 + x 5 + x 6 + x 7 There have been extensive studies on the coefficients of cyclotomic polynomials [21,4,3,11,19,15,14,25,5,16,12,6,24,10,13,7,8], and more recently, on inverse cyclotomic polynomials [22,5,8].…”