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A275867
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Number of simple disconnected asymmetric graph on n vertices.
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2
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0, 0, 0, 0, 0, 0, 8, 144, 3552, 131452, 7840396, 797524408
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refs;
listen;
history;
text;
internal format)
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OFFSET
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1,7
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COMMENTS
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For 2 < n < 12, a(n) = A124059(n-1) (connected asymmetric graphs). This is because the singleton is the only asymmetric graph with fewer than 6 vertices, so in a disconnected asymmetric graph with fewer than 12 vertices one connected component must be the singleton, and it cannot occur more than once. - Falk Hüffner, Jan 16 2020
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REFERENCES
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1
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LINKS
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FORMULA
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MATHEMATICA
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A[s_Integer] := With[{s6 = StringPadLeft[ToString[s], 6, "0"]}, Cases[ Import[ "https://oeis.org/A" <> s6 <> "/b" <> s6 <> ".txt", "Table"], {_, _}][[All, 2]]];
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CROSSREFS
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Cf. A003400 (not-necessarily connected simple asymmetric graphs).
Cf. A124059 (connected simple asymmetric graphs).
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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