if n has this distinction.
A congruence class Zn (zee en) is a field if and only if n is a member of the set formed by these numbers The existence of arbitrarily long arithmetic progressions of them was proven by Green and Tao.  One theorem about these numbers states that a number a is congruent to a to the n mod n if n has this distinction. If n divides a times b and n is one of these, then n divides a or b according to Euclid's Lemma.  They can be found using the Sieve of Eratosthenes, and another result by Euclid states that there are an infinite number of them. For 10 points, name these positive integers which have no positive integer divisors other than themselves and 1.
A congruence class Zn (zee en) is a field if and only if n is a member of the set formed by these numbers
prime numbers