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A033995
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Number of bipartite graphs with n nodes.
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25
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1, 1, 2, 3, 7, 13, 35, 88, 303, 1119, 5479, 32303, 251135, 2527712, 33985853, 611846940, 14864650924, 488222721992, 21712049275198, 1308300679611469, 106897965189674291, 11852113048215107822, 1784730721403509209215, 365323537513403184463273
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listen;
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OFFSET
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0,3
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COMMENTS
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All bipartite graphs are perfect. - Falk Hüffner, Nov 27 2015
EULER transform of A005142 [1, 1, 1, 3, 5, 17, ...] is [1, 2, 3, 7, 13, ...]. - Michael Somos, May 13 2019
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REFERENCES
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R. C. Read and R. J. Wilson, An Atlas of Graphs, Oxford, 1998.
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LINKS
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P. Erdős, D. J. Kleitman, and B. L. Rothschild, Asymptotic enumeration of k_n-free graphs. In Colloquio Internazionale sulle Teorie Combinatorie, (Rome, 1973), Tomo II, Atti dei Convegni Lincei, No. 17, pp. 19-27. Accad. Naz. Lincei, Rome.
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EXAMPLE
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For n=1: o; n=2: o o, o-o; n=3: o o o, o o-o, o-o-o; n=4: o o o o, o o o-o, o-o o-o, o o-o-o, o-o-o-o, K_{2,2}, K_{3,1}. - Michael Somos, May 13 2019
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MATHEMATICA
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A005142 = Cases[Import["https://oeis.org/A005142/b005142.txt", "Table"], {_, _}][[All, 2]];
(* EulerTransform is defined in A005195 *)
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CROSSREFS
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KEYWORD
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nonn,nice
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AUTHOR
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Ronald C. Read
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EXTENSIONS
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a(0)=1 prepended and terms a(21) and beyond from Andrew Howroyd, Sep 05 2018
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STATUS
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approved
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