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A163666
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Numbers n such that n=prime(sigma(phi(pi(n)))).
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1
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2, 5, 47, 107, 1613, 5653, 21557, 230047, 821603, 8145173, 47073007, 68939141, 76040521, 196388147, 240595631, 433046543, 1085166671, 2269551127, 4670405591, 9784786813, 104484802043, 420065905307, 474962067289, 2616252796471, 5804170333301
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OFFSET
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1,1
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COMMENTS
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It is obvious that all terms are primes.
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LINKS
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FORMULA
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MATHEMATICA
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Do[If[n=Prime[m]; m==DivisorSigma[1, EulerPhi[PrimePi[n]]], Print[n]], {m, 235000000}]
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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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