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Search: id:A056075
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| A056075 |
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Numbers n such that n | Sigma(n) - d(n). |
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+0
3
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| 1, 4, 56, 7192, 7232, 7912, 10792, 17272, 30592, 114256, 2154584, 3428368, 44375136, 89245784
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OFFSET
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1,2
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COMMENT
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Or, numbers n such that signa[n]=k.n+d[n] for some k.
For most terms>4, sigma[n]=2n+d[n], i.e. k=2. However, for the 12th term, k=3.
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FORMULA
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Numbers n such that Mod[A000203(n), n]=A000005(n) or A054024(n)=A000005(n). - Labos E. (labos(AT)ana.sote.hu), Apr 12 2002
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MATHEMATICA
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Do[If[Mod[DivisorSigma[1, n]-DivisorSigma[0, n], n]==0, Print[n]], {n, 1, 10^8}]
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CROSSREFS
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Cf. A000203, A000005, A054024.
Sequence in context: A089516 A000573 A070019 this_sequence A000315 A080984 A071579
Adjacent sequences: A056072 A056073 A056074 this_sequence A056076 A056077 A056078
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KEYWORD
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nonn
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AUTHOR
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Robert G. Wilson v (rgwv(AT)rgwv.com), Jul 26 2000
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