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A290289
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The number of maximal subsemigroups of the monoid of partial orientation-preserving and reversing injective mappings on the set [1..n].
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1
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2, 2, 5, 4, 7, 7, 10, 4, 5, 9, 14, 7, 16, 11, 11, 5, 19, 7, 22, 9, 13, 16, 26, 7, 8, 17, 6, 11, 32, 12, 35, 4, 16, 22, 15, 8, 40, 23, 19, 10, 44, 14, 47, 15, 11, 28, 50, 7, 10, 9, 23, 18, 56, 7, 19, 12, 25, 34, 62, 12, 65, 35, 13, 5
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OFFSET
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1,1
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LINKS
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FORMULA
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MATHEMATICA
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a[1] = a[2] = 2; a[n_] := PrimeNu[n-1] + DivisorSum[n, Identity, PrimeQ]+1; Array[a, 64] (* Jean-François Alcover, Feb 18 2019 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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