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A054949
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Number of labeled semi-strong digraphs on n nodes with an odd number of components.
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1
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1, 1, 19, 1612, 565276, 734799976, 3523103676184, 63519230066936512, 4400411105398828102336, 1190433708177460323642937216, 1270463865199882936737403300783744, 5381067966904826663696685903449569172992, 90765788839502187660342772995967835888789034496
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OFFSET
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1,3
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LINKS
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Table of n, a(n) for n=1..13.
V. A. Liskovets, Some easily derivable sequences, J. Integer Sequences, 3 (2000), #00.2.2.
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FORMULA
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a(n) = (A054948(n) + A054947(n))/2. - Andrew Howroyd, Sep 10 2018
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CROSSREFS
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Cf. A054947, A054948, A054950.
Sequence in context: A217830 A002115 A223498 * A242564 A068748 A289736
Adjacent sequences: A054946 A054947 A054948 * A054950 A054951 A054952
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KEYWORD
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nonn,easy
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AUTHOR
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N. J. A. Sloane, May 24 2000
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EXTENSIONS
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More terms from Vladeta Jovovic, Mar 11 2003
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STATUS
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approved
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