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A000717
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Number of graphs with n nodes and floor(n(n-1)/4) edges.
(Formerly M2599 N1027)
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5
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1, 1, 1, 3, 6, 24, 148, 1646, 34040, 1358852, 106321628, 16006173014, 4525920859198, 2404130854745735, 2426376196165902704, 4648429222263945620900, 16788801124652327714275292, 114722035311851620271616102401
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OFFSET
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1,4
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COMMENTS
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This is the largest number of graphs with n vertices that all have the same number of edges. a(n) <= A371161(n). - Allan Bickle, Apr 18 2024
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REFERENCES
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J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 146.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
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EXAMPLE
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There are three graphs with 4 vertices and 3 edges, K_3 U K_1, K_{1,3}, and P_4, so a(4) = 3. - Allan Bickle, Apr 18 2024
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CROSSREFS
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KEYWORD
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nonn,nice,changed
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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