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A058133
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Number of monoids (semigroups with identity) of order n, considered to be equivalent when they are isomorphic or anti-isomorphic (by reversal of the operator).
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8
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0, 1, 2, 6, 27, 156, 1373, 17730, 858977, 1844075697, 52991253973742
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OFFSET
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0,3
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LINKS
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FORMULA
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CROSSREFS
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KEYWORD
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nonn,more,hard
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AUTHOR
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EXTENSIONS
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a(8) and a(9) from Distler & Kelsey (2008), added by N. J. A. Sloane, Jul 10 2009
a(10) from Distler & Kelsey (2009), added by Max Alekseyev, Jul 13 2009
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STATUS
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approved
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