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Search: id:A109659
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| A109659 |
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Numbers n such that the sum of the digits of sigma(n)^n is divisible by n. |
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+0
1
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| 1, 15, 20, 34, 42, 44, 50, 101, 107, 558, 584, 750, 1491, 2793, 2889
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Next term after 2889, if it exists, is greater than 10000.
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EXAMPLE
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The digits of sigma(1491)^1491 sum to 22365 and 22365 is divisible by 1491, so 1491 is in the sequence.
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MATHEMATICA
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Do[s = DivisorSigma[1, n]^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: A086770 A111200 A088494 this_sequence A065148 A093028 A105506
Adjacent sequences: A109656 A109657 A109658 this_sequence A109660 A109661 A109662
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KEYWORD
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base,more,nonn
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AUTHOR
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Ryan Propper (rpropper(AT)stanford.edu), Aug 06 2005
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