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Search: id:A069225
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| A069225 |
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Numbers n such that phi(n) is the reversal of sigma(n). |
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+0
4
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| 1, 65, 2771, 10920, 158804, 2413091, 16636354, 117650080
(list; graph; listen)
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OFFSET
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1,2
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EXAMPLE
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phi(65) = 48 = reversal(84) = reversal(sigma(65)), so 65 belongs to the sequence.
n=2413091, sigma[n]=2528032, phi[n]=2308152=rev[sigma[n]].
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MATHEMATICA
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Select[Range[10^6], EulerPhi[ # ] == FromDigits[Reverse[IntegerDigits[DivisorSigma[1, # ]]]] &]
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CROSSREFS
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Sequence in context: A017728 A004354 A016111 this_sequence A075474 A133853 A078988
Adjacent sequences: A069222 A069223 A069224 this_sequence A069226 A069227 A069228
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KEYWORD
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base,nonn
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AUTHOR
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Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Apr 12 2002
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EXTENSIONS
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a(6)-a(8) from Labos E. (labos(AT)ana.sote.hu), Oct 22 2004
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