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A066172
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Numbers n such that EulerPhi(n+1) - EulerPhi(n) = -d(n).
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0
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5, 7, 33, 135, 231, 273, 435, 465, 824, 6375, 17115, 33704, 86355, 207315, 469395, 603585, 23211885, 37095465, 101216505, 107127111, 124471215, 255080415, 367016055
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| These are the n at which EulerPhi(n) is decreasing at a rate equal to d(n).
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EXAMPLE
| EulerPhi(6) - EulerPhi(5) = 2 - 4 = -2 = -d(5).
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MATHEMATICA
| Select[ Range[ 1, 10^6 ], EulerPhi[ # ] - EulerPhi[ # + 1 ] == DivisorSigma[ 0, # ] & ]
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CROSSREFS
| Sequence in context: A153414 A104815 A007911 * A175667 A018353 A176958
Adjacent sequences: A066169 A066170 A066171 * A066173 A066174 A066175
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KEYWORD
| nonn
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AUTHOR
| Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Dec 14 2001
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EXTENSIONS
| a(17) - a(23) from Harry J. Smith (hjsmithh(AT)sbcglobal.net), Feb 04 2010
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