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A074869
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Numbers n such that sigma(sigma(n) - phi(n)) = phi(n).
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0
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707, 7843, 143591, 274211, 598787, 737807, 861749, 928421, 1515521, 1682203, 1936099, 2223143, 2709473, 2908373, 2985641, 3669919, 3689279, 3825419, 3848851, 4154297, 4429159, 5321743, 5654623, 5678131, 6548899, 8916427, 11403743, 11474267, 12191803, 13340869
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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EXAMPLE
| sigma(sigma(707)-phi(707)) = sigma(816-600) = sigma(216) = 600 = phi(707), so 707 is a term of the sequence.
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MATHEMATICA
| Select[Range[2, 10^6], DivisorSigma[1, DivisorSigma[1, # ] - EulerPhi[ # ]] == EulerPhi[ # ] &]
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CROSSREFS
| Sequence in context: A126830 A005845 A183795 * A188098 A059312 A114923
Adjacent sequences: A074866 A074867 A074868 * A074870 A074871 A074872
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KEYWORD
| nonn
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AUTHOR
| Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Sep 12 2002
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EXTENSIONS
| a(9)-a(30) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Jan 19 2012
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