Journal of Applied Mathematics and Stochastic Analysis
Volume 4 (1991), Issue 3, Pages 175-186
doi:10.1155/S104895339100014X
    
    
    On the distribution of the number of vertices in layers of random trees
    
    1Case Western Reserve University, Cleveland, Ohio, USA
22410 Newbury Drive, Cleveland Heights 44118, OH, USA
    
    
    
    Received 1 May 1991; Revised 1 June 1991
    	
    
       
    Copyright © 1991 Lajos  Takács. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
     
    
    
   
 
Abstract
Denote by Sn the set of all distinct rooted trees with n labeled 
vertices. A tree is chosen at random in the set Sn, assuming that all the 
possible nn−1 choices are equally probable. Define τn(m) as the number 
of vertices in layer m, that is, the number of vertices at a distance m 
from the root of the tree. The distance of a vertex from the root is the 
number of edges in the path from the vertex to the root. This paper is 
concerned with the distribution and the moments of τn(m) and their 
asymptotic behavior in the case where m=[2αn], 0<α<∞ and n→∞. 
In addition, more random trees, branching processes, the Bernoulli 
excursion and the Brownian excursion are also considered.