Korean J. Math. Vol. 20 No. 2 (2012) pp.255-261
DOI: https://doi.org/10.11568/kjm.2012.20.2.255

A REFINEMENT FOR ORDERED LABELED TREES

Article Sidebar

PDF
Published: Jun 30, 2012

Main Article Content

Seunghyun Seo
Heesung Shin

Abstract

Let O_n be the set of ordered labeled trees on {0, . . . , n}. A maximal decreasing subtree of an ordered labeled tree is defined by the maximal ordered subtree from the root with all edges being decreasing. In this paper, we study a new refinement O_{n,k} of O_n, which is the set of ordered labeled trees whose maximal decreasing subtree has k + 1 vertices.



Article Details

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.