Find all integers n≥2 with the following property:There exists three distinct primes p,q,r such that
whenever a1,a2,a3,⋯,an are n distinct positive integers with the property that at least one of p,q,r divides aj−ak ∀1≤j≤k≤n,
one of p,q,r divides all of these differences. number theory proposednumber theory