Title
Generalized Stirling Permutations and Forests: Higher-Order Eulerian and Ward Numbers.
Abstract
We define a new family of generalized Stirling permutations that can be interpreted in terms of ordered trees and forests. We prove that the number of generalized Stirling permutations with a fixed number of ascents is given by a natural three-parameter generalization of the well-known Eulerian numbers. We give the generating function for this new class of numbers and, in the simplest cases, we find closed formulas for them and the corresponding row polynomials. By using a non-trivial involution our generalized Eulerian numbers can be mapped onto a family of generalized Ward numbers, forming a Riordan inverse pair, for which we also provide a combinatorial interpretation.
Year
Venue
Keywords
2015
ELECTRONIC JOURNAL OF COMBINATORICS
generalized Stirling permutations,increasing trees and forests,generalized Eulerian numbers,generalized Ward numbers
DocType
Volume
Issue
Journal
22
3.0
ISSN
Citations 
PageRank 
1077-8926
0
0.34
References 
Authors
0
3
Name
Order
Citations
PageRank
J. Fernando Barbero G.121.18
JesúS Salas271.69
Eduardo J. S. Villaseñor321.18