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The Smallest Cubic Graphs of Girth Nine

Published online by Cambridge University Press:  12 September 2008

Gunnar Brinkmann
Affiliation:
Fakultät für Mathematik, Universität Bielefeld, D 33501 Bielefeld, Germany (e-mail: gunnar@mathematik.uni-bielefeld.de)
Brendan D. Mckay
Affiliation:
Department of Computer Science, Australian National University, ACT 0200, Australia (e-mail: bdm@cs.anu.edu.au)
Carsten Saager
Affiliation:
Mühlenstr. 7, D 49196 Bad Laer, Germany

Abstract

We describe two computational methods for the construction of cubic graphs with given girth. These were used to produce two independent proofs that the (3,9)-cages, defined as the smallest cubic graphs of girth 9, have 58 vertices. There are exactly 18 such graphs. We also show that cubic graphs of girth 11 must have at least 106 vertices and cubic graphs of girth 13 must have at least 196 vertices.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1995

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