MIT Combinatorics Seminar A Generelized Enumeration of Labeled Trees Seunghyun Seo (Brandeis University) shseo@brandeis.edu Wednesday March 30, 2005   4:15 pm    Room 2-338 ABSTRACT In this talk, we'll give a simple combinatorial explanation of a formula of A. Postnikov relating bicolored rooted trees to bicolored binary trees. We'll also present generalized formula for the number of labeled k-ary trees, rooted labeled trees, and labeled plane trees. Combinatorial explanations of these formulas will be discussed too. This is joint work with Ira Gessel.