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A058275
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Number of connected 5-regular simple graphs on 2n vertices with girth at least 4.
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18
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1, 0, 0, 0, 0, 1, 1, 7, 388, 406824, 1125022325, 3813549359274
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OFFSET
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0,8
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COMMENTS
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The null graph on 0 vertices is vacuously connected and 5-regular; since it is acyclic, it has infinite girth. [From Jason Kimberley, Jan 30 2011]
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REFERENCES
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M. Meringer, Fast Generation of Regular Graphs and Construction of Cages. Journal of Graph Theory, 30 (1999), 137-146. [From Jason Kimberley, Jan 30 2011]
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LINKS
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FORMULA
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CROSSREFS
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5-regular simple graphs on 2n vertices with girth at least 4: this sequence (connected), A185254 (disconnected), A185354 (not necessarily connected).
Connected 5-regular simple graphs with girth at least g: A006821 (g=3), this sequence (g=4), A205295 (g=5).
Connected 5-regular simple graphs with girth exactly g: A184953 (g=3), A184954 (g=4), A184955 (g=5). (End)
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KEYWORD
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nonn,more,hard
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AUTHOR
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EXTENSIONS
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Terms a(10) and a(11) appended, from running Meringer's GENREG for 3.8 and 7886 processor days at U. Ncle., by Jason Kimberley on Jun 28 2010.
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STATUS
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approved
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