The prime power conjecture is true for \(n<2,000,000\)
Summary: The Prime Power Conjecture (PPC) states that abelian planar difference sets of order \(n\) exist only for \(n\) a prime power. Evans and Mann verified this for cyclic difference sets for \(n\leq 1600\). In this paper we verify the PPC for \(n\leq 2,000,000\), using many necessary conditions on the group of multipliers.
scientific article; zbMATH DE number 741547