Abstract
The previously known ways to count acyclic digraphs, both labeled and unlabeled, are reviewed. Then a new method of enumerating unlabeled acyclic digraphs is developed. It involves computing the sum of the cyclic indices of the automorphism groups of the acyclic digraphs, achieving a considerable gain in efficiency through an application of the inclusion-exclusion principle. Numerical results are reported on, and a table of the numbers of unlabeled acyclic digraphs on up to 18 points is included.
The author is grateful to the Australian Research Grants Committee for providing the support necessary for the programming of all the numerical work. This was performed by Dr. Paul Butler. The running times reported were observed on a PDP-11/45 with secondary storage on an RK05 disc.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsPreview
Unable to display preview. Download preview PDF.
References
W. Burnside, Theory of Groups of Finite Order. 2nd ed., Cambridge Univ. Press, London, 1911. Reprinted by Dover, New York, 1955.
F. Harary and E.M. Palmer, Graphical Enumeration. Academic Press, New York, 1973.
C.L. Liu, Introduction to Combinatorial Mathematics. McGraw-Hill, New York, 1968.
G. Pólya, Kombinatorische Anzahlbestimmungen für Gruppen, Graphen, und chemische Verbindungen, Acta Math. 68 (1937) 145–254.
J.H. Redfield, The theory of group reduced distributions, Amer. J. Math. 49 (1927) 433–455.
R.W. Robinson, Enumeration of nonseparable graphs, J. Combinatorial Theory 9 (1970) 327–356.
R.W. Robinson, Enumeration of acyclic digraphs, Combinatorial Mathematics and Its Applications. (R.C. Bose et al., eds) Univ. of North Carolina, Chapel Hill (1970) 391–399.
R.W. Robinson, Counting labeled acyclic digraphs, New Directions in the Theory of Graphs. (Frank Harary, ed.) Academic Press, New York (1973) 239–273.
Editor information
Rights and permissions
Copyright information
© 1977 Springer-Verlag
About this paper
Cite this paper
Robinson, R.W. (1977). Counting unlabeled acyclic digraphs. In: Little, C.H.C. (eds) Combinatorial Mathematics V. Lecture Notes in Mathematics, vol 622. Springer, Berlin, Heidelberg. https://doi.org/10.1007/BFb0069178
Download citation
DOI: https://doi.org/10.1007/BFb0069178
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-08524-9
Online ISBN: 978-3-540-37020-8
eBook Packages: Springer Book Archive