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A072500
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Product of divisors of n which are >= n^(1/2).
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16
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1, 2, 3, 8, 5, 18, 7, 32, 27, 50, 11, 288, 13, 98, 75, 512, 17, 972, 19, 1000, 147, 242, 23, 13824, 125, 338, 243, 2744, 29, 27000, 31, 4096, 363, 578, 245, 419904, 37, 722, 507, 64000, 41, 86436, 43, 10648, 6075, 1058, 47, 1769472, 343, 12500, 867, 17576, 53
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OFFSET
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1,2
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COMMENTS
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a(n) = n iff n is not a composite number.
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LINKS
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EXAMPLE
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The divisors of 20 are 1, 2, 4, 5, 10 and 20. a(20) = 5*10*20= 1000.
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MATHEMATICA
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Table[Times @@ Select[Divisors[n], # >= Sqrt[n] &], {n, 1, 55}]
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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Corrected a(16) by Harvey P. Dale, Oct 06 2011
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STATUS
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approved
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