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A293605
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Primes p such that phi(p-1) < (p-1)/4.
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1
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211, 331, 421, 631, 661, 991, 1051, 1171, 1321, 1471, 1951, 2311, 2341, 2521, 2731, 2971, 3121, 3301, 3361, 3511, 3571, 3631, 4201, 4621, 4831, 4951, 5281, 5851, 5881, 6007, 6091, 6271, 6301, 7351, 7411, 7561, 7591, 8191, 8581, 8779, 8821, 8971, 9241, 9283, 9661, 9871, 9901
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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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Select[Prime[Range[1500]], EulerPhi[#-1]<(#-1)/4&] (* Harvey P. Dale, Oct 27 2018 *)
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PROG
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(PARI) lista(nn) = forprime(p=2, nn, if (eulerphi(p-1) < (p-1)/4, print1(p, ", ")));
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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