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Search: id:A096841
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| A096841 |
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Numbers n such that sum of divisors of these numbers gives a decimal repdigit. |
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+0
6
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| 1, 2, 3, 4, 5, 7, 43, 146, 365, 438, 443, 803, 887, 2221, 4442, 6663, 8887, 87876, 88183, 153837, 250244, 285597, 292860, 296294, 302877, 307674, 344268, 351612, 380718, 403398, 423260, 441821, 444443, 550238, 579038, 584438, 588974, 593163, 600363
(list; graph; listen)
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OFFSET
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1,2
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EXAMPLE
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n=43:sigma[43]=44; regular solutions:repdigit-1=prime.
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MATHEMATICA
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rd[x_] := Length[Union[IntegerDigits[x]]] Do[s = rd[DivisorSigma[1, n]]; s1 = DivisorSigma[1, n]; If[Equal[s, 1], Print[{n, s1}]; ta[[u]] = n; u = u + 1], {n, 1, 1000000}]; ta; DivisorSigma[1, ta]
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CROSSREFS
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Cf. A096503-A096508, A096841-A096846, A000203.
Sequence in context: A063737 A135709 A028980 this_sequence A029963 A028986 A063948
Adjacent sequences: A096838 A096839 A096840 this_sequence A096842 A096843 A096844
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KEYWORD
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base,nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Jul 15 2004
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