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A079571
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Number of unlabeled, connected graphs on n vertices whose complements are bipartite.
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2
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1, 1, 1, 2, 5, 11, 32, 85, 299, 1115, 5474, 32298, 251129, 2527706, 33985846, 611846933, 14864650916, 488222721984, 21712049275189, 1308300679611460, 106897965189674281, 11852113048215107812, 1784730721403509209204, 365323537513403184463262
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OFFSET
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0,4
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COMMENTS
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Equivalently, number of bipartite graphs whose complement is connected. The only bipartite graphs with disconnected complement are complete bipartite graphs. - Falk Hüffner, Jan 22 2016
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LINKS
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FORMULA
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MATHEMATICA
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A005142 = Import["https://oeis.org/A005142/b005142.txt", "Table"][[All, 2]];
etr[p_] := Module[{b}, b[n_] := b[n] = If[n == 0, 1, Sum[Sum[d*p[d], {d, Divisors[j]}]*b[n - j], {j, 1, n}]/n]; b];
a[n_] := b[n] - Floor[n/2];
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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Corrected and extended using formula by Falk Hüffner, Jan 22 2016
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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