International Journal of Mathematics and Mathematical Sciences
Volume 2005 (2005), Issue 19, Pages 3057-3073
doi:10.1155/IJMMS.2005.3057

Prime divisors of some shifted products

Eric Levieil , Florian Luca and Igor E. Shparlinski

Département d'Informatique, École Normale Supérieure 45, rue d'Ulm, Paris Cedex 05 75230, France

Abstract

We study prime divisors of various sequences of positive integers A(n)+1, n=1,,N, such that the ratios a(n)=A(n)/A(n1) have some number-theoretic or combinatorial meaning. In the case a(n)=n, we obviously have A(n)=n!, for which several new results about prime divisors of n!+1 have recently been obtained.