Tree
A tree is an undirected graph G that satisfies any of the following equivalent conditions:
• G is See more

• Every tree is a bipartite graph. A graph is bipartite if and only if it contains no cycles of odd length. Since a tree contains no cycles at all, it is … See more

Labeled trees
Cayley's formula states that there are n trees on n labeled vertices. A classic proof uses Prüfer sequences, which naturally show a stronger result: the number of trees with vertices 1, 2, …, n of degrees d1, d2, …, dn … See more

• A path graph (or linear graph) consists of n vertices arranged in a line, so that vertices i and i + 1 are connected by an edge for i = 1, …, n – 1.
• A starlike tree consists of a central vertex called root and several path graphs attached to it. More formally, a tree is starlike if it has … See more

• Decision tree
• Hypertree
• Multitree
• Pseudoforest See more

1. ^ Bender & Williamson 2010, p. 171.
2. ^ Bender & Williamson 2010, p. 172.
3. ^ Deo 1974, p. 206.
4. ^ See Harary & Sumner (1980). See more

• Diestel, Reinhard (2005), Graph Theory (3rd ed.), Berlin, New York: Springer-Verlag, ISBN 978-3-540-26183-4.
• Flajolet, Philippe; Sedgewick, Robert (2009), Analytic Combinatorics, Cambridge University Press, ISBN See more