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A109889
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Numbers n such that 3^n - phi(n) is prime.
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0
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1, 4, 5, 6, 20, 22, 25, 46, 47, 214, 822, 985, 3273, 3590, 4658, 4768, 17250, 38697
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OFFSET
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1,2
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COMMENTS
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Terms less than 1000 correspond to certified primes. Next term is greater than 10000.
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LINKS
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MATHEMATICA
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Do[If[PrimeQ[3^n - EulerPhi[n]], Print[n]], {n, 1, 10^4}]
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CROSSREFS
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KEYWORD
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hard,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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