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 A069225 Numbers n such that phi(n) is the reversal of sigma(n). 7
 1, 65, 2771, 10920, 158804, 2413091, 16636354, 117650080, 140766297, 630947067, 4639526938, 153896850898 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(13) > 10^12. - Giovanni Resta, Nov 03 2012 LINKS EXAMPLE 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]]. MATHEMATICA Select[Range[10^6], EulerPhi[ # ] == FromDigits[Reverse[IntegerDigits[DivisorSigma[1, # ]]]] &] CROSSREFS Cf. A000010, A000203, A004086. Sequence in context: A217675 A237858 A075474 * A211960 A293695 A133853 Adjacent sequences:  A069222 A069223 A069224 * A069226 A069227 A069228 KEYWORD base,nonn AUTHOR Joseph L. Pe, Apr 12 2002 EXTENSIONS a(6)-a(8) from Labos Elemer, Oct 22 2004 a(9)-a(11) from Donovan Johnson, Jan 14 2011 a(12) from Giovanni Resta, Nov 03 2012 STATUS approved

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Last modified August 8 08:27 EDT 2020. Contains 336293 sequences. (Running on oeis4.)