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A066694
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Numbers n such that EulerPhi(sigma(n)) > n.
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1
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4, 9, 16, 18, 25, 32, 36, 48, 50, 64, 72, 81, 84, 98, 100, 112, 144, 156, 162, 192, 196, 200, 225, 252, 256, 288, 289, 300, 324, 336, 338, 372, 392, 400, 432, 448, 450, 468, 484, 512, 576, 578, 624, 625, 648, 676, 700, 722, 729, 756, 768, 784, 800, 882, 900
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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LINKS
| Harry J. Smith, Table of n, a(n) for n=1,...,1000
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FORMULA
| It seems that a(n) is asymptotic to C*n*Log(n)^2 with C=1.38.... - Benoit Cloitre (benoit7848c(AT)orange.fr), Aug 07 2002
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MATHEMATICA
| Select[Range[1, 10^3], EulerPhi[DivisorSigma[1, # ]] > # &]
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PROG
| (PARI) { n=0; for (m=1, 10^10, if (eulerphi(sigma(m)) > m, write("b066694.txt", n++, " ", m); if (n==1000, return)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Mar 18 2010]
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CROSSREFS
| Sequence in context: A066925 A122379 A104020 * A102646 A104021 A073804
Adjacent sequences: A066691 A066692 A066693 * A066695 A066696 A066697
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KEYWORD
| easy,nonn
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AUTHOR
| Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Jan 09 2002
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EXTENSIONS
| More terms from Benoit Cloitre (benoit7848c(AT)orange.fr), Jul 31 2002
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