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A076965
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a(1) = 2; thereafter a(n) is the smallest number coprime to a(n-1) and having a(n-1) divisors.
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1
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OFFSET
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1,1
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COMMENTS
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a(7) = 2^18 * 7^16 * 23^12 * 29^10 * 31^4 * 37^4 * 41^4 * 43^4 * 47^4 * 53^4 * 59^2 * 61^2 * 67^2 * 71^2 * 73^2 * 79^2, which has 111 digits [From Nathaniel Johnston, Nov 28 2008]
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LINKS
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EXAMPLE
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a(4) = 15, a(5) = 784 = 2^4*7^2, tau(784) =5*3 = 15 with (784,15) = 1
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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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Added 526121578125 based on its prime factorization of 3^6 * 5^6 * 11 * 13 * 17 * 19, it is the smallest possible number such that gcd(n,784)=1 and d(n)=784. - Kevin Sullivan (kasull88(AT)gmail.com), Nov 24 2008
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STATUS
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approved
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