Abstract. We study ν k (n), the number of partitions of n into k part sizes, and find numerous arithmetic progressions where ν 2 and ν 3 take on values divisible by 2 and 4. Expanding earlier work, we show ν 2 (An + B) ≡ 0 (mod 4) for (A,B) = (36,30), (72,42), (252,114), (196,70), and likely many other progressions for which our method should easily generalize. Of some independent interest, we prove that the overpartition function p(n) ≡ 0 (mod 16) in the first three progressions (the fourth is known), and thereby show that ν 3 (An + B) ≡ 0 (mod 2) in each of these progressions as well, and discuss the relationship between these congruences in more generality. We end with open questions in this area.