摘要

Let Phi(n)(x) = Sigma(phi(n))(k=0) a(n, k)x(k) denote the n-th cyclotomic polynomial. In this note, let p < q < r be odd primes, where q not equivalent to 1 (mod p) and r equivalent to -2 (mod pq), we construct an explicit k such that a(pqr, k) = -2.