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A305564
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Number of finite sets of relatively prime positive integers with least common multiple n.
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4
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1, 1, 1, 2, 1, 7, 1, 4, 2, 7, 1, 32, 1, 7, 7, 8, 1, 32, 1, 32, 7, 7, 1, 136, 2, 7, 4, 32, 1, 193, 1, 16, 7, 7, 7, 322, 1, 7, 7, 136, 1, 193, 1, 32, 32, 7, 1, 560, 2, 32, 7, 32, 1, 136, 7, 136, 7, 7, 1, 3464, 1, 7, 32, 32, 7, 193, 1, 32, 7, 193, 1, 2852, 1, 7
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OFFSET
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1,4
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LINKS
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EXAMPLE
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The a(6) = 7 sets are {1,6}, {2,3}, {1,2,3}, {1,2,6}, {1,3,6}, {2,3,6}, {1,2,3,6}.
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MATHEMATICA
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Table[Length[Select[Rest[Subsets[Divisors[n]]], And[GCD@@#==1, LCM@@#==n]&]], {n, 100}]
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CROSSREFS
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Cf. A001055, A071625, A076078, A181819, A275870, A281116, A285573, A285572, A290103, A304818, A305563, A305565, A305566, A305567.
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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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