Type: Article

On a variant of Giuga numbers

José María Grau; Florian Luca; Antonio M. Oller-Marcén;

Abstract:

In this paper, we characterize the odd positive integers n satisfying the congruence Sigma(n-1)(j=1) j(n-1/2) = 0 ( mod n).We show that the set of such positive integers has an asymptotic density which turns out to be slightly larger than 3/8.