摘要
Let q be a positive integer. The graphs called the q-trees are defined by recursion: the smallest q-tree is the complete graph K_q with q vertices, and a q-tree with n+1 vertices where n≥q is obtained by adding a new vertex adjacent to each of q arbitrarily selected but mutually adjacent vertices of a q-tree with n vertices. Obviously, 1-trees are the graphs which we generally call trees.
