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A147751
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Number of nontrivial (i.e., containing two or more members) subsets of {1,2,3,...,n} whose geometric mean is an integer.
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2
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0, 0, 0, 2, 2, 2, 2, 4, 10, 10, 10, 16, 16, 16, 16, 24, 24, 52, 52, 54
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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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For n=4, (1*4)^(1/2) = 2 and (1*2*4)^(1/3) = 2. No other subset of {1,2,3,4} has integer geometric mean, so a(4)=2.
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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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