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A191975
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Lowest common multiple of all p-1, where prime p divides the n-th primary pseudoperfect number A054377(n).
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1
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OFFSET
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1,2
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COMMENTS
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a(n) is a factor of any exponent k > 0 such that 1^k + 2^k + ... + p^k == 1 (mod p), where p = A054377(n).
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REFERENCES
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J. Sondow and K. MacMillan, Reducing the Erdos-Moser equation 1^n + 2^n + ... + k^n = (k+1)^n modulo k and k^2, Integers 11 (2011), #A34.
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LINKS
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Table of n, a(n) for n=1..8.
J. Sondow and K. MacMillan, Reducing the Erdos-Moser equation 1^n + 2^n + ... + k^n = (k+1)^n modulo k and k^2
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FORMULA
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a(n) = LCM(p-1 : prime p | A054377(n)).
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EXAMPLE
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A054377(3) = 42 = 2*3*7, so a(3) = LCM(2-1,3-1,7-1) = LCM(1,2,6) = 6.
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CROSSREFS
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Cf. A054377.
Sequence in context: A127071 A151333 A190626 * A074015 A074021 A050862
Adjacent sequences: A191972 A191973 A191974 * A191976 A191977 A191978
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KEYWORD
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nonn
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AUTHOR
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Kieren MacMillan, Jun 20 2011
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STATUS
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approved
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