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A066685
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Numbers n such that p(n) is congruent to EulerPhi(n) mod n, where p(n) denotes the n-th prime.
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0
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1, 2, 3, 789, 40087, 238717, 251737, 7847315, 69673727, 2283427137, 2664260621
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OFFSET
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1,2
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COMMENTS
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LINKS
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EXAMPLE
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p(1) = 2 is congruent to 0 mod 1, and EulerPhi(1) = 1 is congruent to 0 mod 1, so 1 is a term of the sequence.
p(3) = 5 is congruent to 2 mod 3, and EulerPhi(3) = 2 is congruent to 2 mod 3, so 3 is a term of the sequence.
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MATHEMATICA
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Select[ Range[ 1, 10^6 ], Mod[ EulerPhi[ # ], # ] == Mod[ Prime[ # ], # ] & ]
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PROG
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(PARI) print1(n=1); forprime(p=3, 1e9, if(p%n++==eulerphi(n), print1(", "n))) \\ Charles R Greathouse IV, Mar 04 2017
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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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