Ternary cyclotomic polynomials having a large coefficient

Yves Gallot, Pieter Moree

Let ${\Phi }_n(x)$ denote the $n$th cyclotomic polynomial. In 1968 Sister Marion Beiter conjectured that $a_n(k)$, the coefficient of $x^k$ in ${\Phi }_n(x)$, satisfies $|a_n(k)|\le (p+1)/2$ i…