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A125571
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Least prime factor of Sum_{k=0..n-1} n^k.
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1
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3, 13, 5, 11, 7, 29, 3, 7, 11, 15797, 5, 53, 3, 11, 17, 10949, 7, 109912203092239643840221, 3, 43, 23, 461, 5, 11, 3, 109, 5, 59, 7, 568972471024107865287021434301977158534824481, 3, 67, 5, 31, 13, 149, 3, 7, 11, 83, 13, 173, 3, 19, 47
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OFFSET
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2,1
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COMMENTS
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The sequence of largest prime factors of numbers generated by the same sum is probably identical to sequence A006486, since (n^n - 1)/(1 + n^2 + ... + n^(n-1)) = n-1.
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LINKS
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EXAMPLE
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The sum 1 + 4 + 4^2 + 4^3 = 85 = 5 * 17 so the third term is 5.
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PROG
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(PARI) a(n) = factor(sum(k=0, n-1, n^k))[1, 1]; \\ Michel Marcus, Aug 20 2013
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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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STATUS
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approved
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