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Search: id:A109658
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| A109658 |
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Numbers n such that the sum of the digits of n^sigma(n) is divisible by n. |
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+0
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| 1, 2, 3, 9, 11, 18, 54, 74, 108, 135, 426, 531, 585, 1361, 3456, 6771, 7245, 7392, 11025, 11957, 21494, 27063, 41952, 68494, 72516
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OFFSET
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1,2
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EXAMPLE
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The sum of the integer digits of 531^sigma(531) is 9558 and 9558 is divisible by 531, so 531 is in the sequence.
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MATHEMATICA
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Do[s = n^DivisorSigma[1, n]; k = Plus @@ IntegerDigits[s]; If[Mod[k, n] == 0, Print[n]], {n, 1, 10000}]
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CROSSREFS
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Sequence in context: A110772 A074338 A111319 this_sequence A110350 A057569 A049618
Adjacent sequences: A109655 A109656 A109657 this_sequence A109659 A109660 A109661
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KEYWORD
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base,nonn
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AUTHOR
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Ryan Propper (rpropper(AT)stanford.edu), Aug 06 2005
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EXTENSIONS
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More terms from Ryan Propper (rpropper(AT)stanford.edu), Oct 10 2005
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