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A248862
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Primes p such that 900*p^2 is in the sequence A248861.
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1
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OFFSET
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1,1
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COMMENTS
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For p>5, an equivalent condition is (240*p*(p-1))^(240*p*(p-1)) == 1 (mod 2821*(1+p+p^2)).
a(9) > 10^12 if it exists. (End)
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LINKS
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MATHEMATICA
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lastP=2; lst={2}; While[lastP<200, If[
Mod[EulerPhi[900*NextPrime[lastP]^2]^EulerPhi[900*NextPrime[lastP]^2], DivisorSigma[1, 900*NextPrime[lastP]^2]]==1,
AppendTo[lst, NextPrime[lastP]]]; lastP=NextPrime[lastP]]; lst (* Ivan N. Ianakiev, Dec 15 2014 *)
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CROSSREFS
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KEYWORD
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nonn,more,hard
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AUTHOR
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STATUS
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approved
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