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A194085
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Strong Achilles numbers: Achilles numbers m such that phi(m) is also an Achilles number, where phi(m) denotes Euler's totient function of m.
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1
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500, 864, 1944, 2000, 2592, 3456, 5000, 10125, 10368, 12348, 12500, 16875, 19652, 19773, 30375, 31104, 32000, 33275, 37044, 40500, 49392, 50000, 52488, 55296, 61731, 64827, 67500, 69984, 78608, 80000, 81000, 83349, 84375, 93312, 108000
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OFFSET
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1,1
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LINKS
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MATHEMATICA
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achillesQ[n_] := With[{ee = FactorInteger[n][[All, 2]]}, Min[ee] > 1 && GCD @@ ee == 1];
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PROG
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(PARI) isA(n)=!ispower(n) && ispowerful(n)
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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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