Let $n$ be a positive integer. Find all $n$- rows $( a_1 , a_2 ,..., a_n )$ of different positive integers such that $$ \frac{(a_1 + d ) (a_2 + d ) \cdot\cdot\cdot ( a_n + d )}{a_1a_2\cdot \cdot \cdot a_n }$$is integer for every integer $d\ge 0$
Problem
Source: Rioplatense Olympiad 2018 level 3 p5
Tags: number theory, Integer, Product, Products, positive integers