The Tutte bicubic graph conjecture asserted that there are no 3-connected bicubic nonhamiltonian graphs (Tutte 1971/72). However, a counterexample was found by
J. D. Horton in 1976 (Gropp 1990), and several smaller counterexamples
are now known.
Known small counterexamples are summarized in the following table and illustrated above.
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J. A. and Murty, U. S. R. Graph
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M. N. "Non-Hamiltonian 3-Connected Cubic Partite Graphs." Dept. of
Math. Research Report No. 28. Melbourne, Australia: University of Melbourne,
1981.Ellingham, M. N. "Constructing Certain Cubic Graphs."
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held at the University of Queensland, Brisbane, August 24-28, 1981 (Ed. E. J. Billington,
S. Oates-Williams, and A. P. Street). Berlin, Germany: Springer-Verlag,
pp. 252-274, 1982.Ellingham, M. N. and Horton, J. D.
"Non-Hamiltonian 3-Connected Cubic Bipartite Graphs." J. Combin. Th.
Ser. B34, 350-353, 1983.Georges, J. P. "Non-Hamiltonian
Bicubic Graphs." J. Combin. Th. B46, 121-124, 1989.Gropp,
H. "Configurations and the Tutte Conjecture." Ars Combin.29A,
171-177, 1990.Grünbaum, B. "3-Connected Configurations
with No Hamiltonian Circuit." Bull. Inst. Combin. Appl.46, 15-26,
2006.Grünbaum, B. Configurations
of Points and Lines. Providence, RI: Amer. Math. Soc., p. 311, 2009.Horton,
J. D. "On Two-Factors of Bipartite Regular Graphs." Disc. Math.41,
35-41, 1982.Owens, P. J. "Bipartite Cubic Graphs and a Shortness
Exponent." Disc. Math.44, 327-330, 1983.Tutte, W. T.
"On the 2-Factors of Bicubic Graphs." Disc. Math.1, 203-208,
1971/72.