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Search: id:A072500
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| A072500 |
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Product of divisors of n which are >= n^(1/2). |
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+0
4
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| 1, 2, 3, 8, 5, 18, 7, 32, 27, 50, 11, 288, 13, 98, 75, 128, 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
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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a(n) = n iff n is not a composite number.
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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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Cf. A072499, A072501 & A070038.
Sequence in context: A070935 A095164 A075384 this_sequence A062956 A053650 A119794
Adjacent sequences: A072497 A072498 A072499 this_sequence A072501 A072502 A072503
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KEYWORD
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nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Jul 20 2002
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EXTENSIONS
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Edited by Robert G. Wilson v (rgwv(AT)rgwv.com), Jul 22 2002
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