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A086560
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Start of first run of n successive numbers in which i-th number has exactly i distinct prime divisors for i = 1..n.
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10
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OFFSET
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1,1
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REFERENCES
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J.-M. De Koninck, Ces nombres qui nous fascinent, Entry 64, p. 23, Ellipses, Paris 2008.
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LINKS
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EXAMPLE
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a(3) = 64, as 64 has 1, 65 has 2 and 66 has 3 prime divisors: 64 = 2^6, 65 = 5*13 and 66 = 2*3*11.
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CROSSREFS
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KEYWORD
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nonn,hard,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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