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A066994
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Numbers n such that phi(n) divides n*sigma(n).
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1
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1, 2, 3, 4, 6, 8, 10, 12, 14, 15, 16, 18, 20, 21, 24, 26, 27, 30, 32, 35, 36, 39, 40, 42, 48, 54, 55, 56, 60, 63, 64, 70, 72, 78, 80, 84, 88, 96, 98, 104, 105, 108, 110, 114, 116, 120, 125, 126, 128, 135, 140, 144, 147, 150, 155, 156, 160, 162, 165, 168, 189, 190, 192
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OFFSET
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1,2
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LINKS
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MATHEMATICA
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Select[Range[200], Divisible[# DivisorSigma[1, #], EulerPhi[#]]&] (* Harvey P. Dale, Aug 23 2019 *)
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PROG
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(PARI) { n=0; for (m=1, 10^10, if ((m*sigma(m)) % eulerphi(m) == 0 , write("b066994.txt", n++, " ", m); if (n==1000, return)) ) } \\ Harry J. Smith, Apr 23 2010
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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