Given integers a , m≥1 with gcd(a,m)=1 and caaae71c954213bde2906" title="Click to view the MathML source">s≥2, let Hs(a,m) be the following set of integral points
We obtain upper bounds on the number of vertices of the convex hull of Hs(a,m). These bounds generalise those known for s=2, although our approach is different.