COUNTING SELF-CONVERSE ORIENTED TREES
Su-Jeong Choi, Lee Chang-Woo · Communications of the Korean Mathematical Society · 2001
We classify self-converse oriented trees into two types, namely, bicentral self-converse oriented trees and central ones, accord- ing to their centers and characterize these two types. Using charac- terizations and Polya enumeration theorem, we derive the ordinary generating function for self-converse oriented trees.