On a variant of k-plane trees
Keywords:
$k$-plane tree, $k_1$-plane tree, root degree, eldest child, youngest child, forest
Abstract
In this paper, we introduce a class of plane trees whose vertices receive labels from the set {1,2,...,k} such that the sumof labels of adjacent vertices does not exceed k+1 and all vertices of label 1 are always on the left of all other vertices.
Using generating functions, we enumerate these trees by number of vertices and label of the root, root degree, label of the
eldest or youngest child of the root and forests.