Enumeration and Asymptotic Properties of Unlabeled Outerplanar Graphs

We determine the exact and asymptotic number of unlabeled outerplanar graphs. The exact number gn of unlabeled outerplanar graphs on n vertices can be computed in polynomial time, and gn is asymptotically g n−5/2ρ−n, where g ≈ 0.00909941 and ρ−1 ≈ 7.50360 can be approximated. Using our enumerative results we investigate several statistical properties of random unlabeled outerplanar graphs on n vertices, for instance concerning connectedness, the chromatic number, and the number of edges. To obtain the results we combine classical cycle index enumeration with recent results from analytic combinatorics.

• Type: Journal
• Year: 2007
• Where: COMBINATORICS
• Authors: Manuel Bodirsky, Éric Fusy, Mihyun Kang, Stefan Vigerske
• Keywords: COMBINATORICS 2007, Exact Number Gn, Unlabeled Outerplanar, Unlabeled Outerplanar Graphs