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A067385
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a(n) is smallest x such that sigma(phi(x))/sigma(x) = n.
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6
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OFFSET
| 1,2
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COMMENTS
| A023199(6) < a(6) <= 1794819234390989. - Donovan Johnson, Oct 24 2011
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MATHEMATICA
| a[ n_ ] := For[ x=1, True, x++, If[ DivisorSigma[ 1, EulerPhi[ x ] ]/DivisorSigma[ 1, x ]==n, Return[ x ] ] ]
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CROSSREFS
| Cf. A033631, A066831, A067382, A067383, A067384, A197952.
Sequence in context: A001570 A020544 A009015 * A097260 A178303 A158548
Adjacent sequences: A067382 A067383 A067384 * A067386 A067387 A067388
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KEYWORD
| more,nonn
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AUTHOR
| Dean Hickerson (dean.hickerson(AT)yahoo.com), Jan 20 2002
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EXTENSIONS
| a(5) from Vim Wenders (vim(AT)gmx.li), Mar 11 2007
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