This talk involves a certain sum of rational functions in two parameters q and t which was conjectured by Garsia and Haiman to simplify to a polynomial in q and t with nonnegative coefficients. They called this the q,t-Catalan sequence since if q and t are set to one the rational sum simplifies to the nth Catalan number. We introduce a refined version of their conjecture based on an empirical discovery by the speaker, and discuss how the speaker and Garsia proved this and thus the original conjecture.