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A339878
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Carmichael numbers k such that phi(k) divides p*(k - 1) for some prime factor p of k - 1.
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4
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OFFSET
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1,1
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COMMENTS
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Also, for all ten, a(n) == 1 (mod 64). (Cf. a similar comment in A338998).
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LINKS
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MATHEMATICA
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carmichaels = Cases[Import["https://oeis.org/A002997/b002997.txt", "Table"], {_, _}][[;; , 2]]; q[n_] := Module[{p = FactorInteger[n - 1][[;; , 1]], phi = EulerPhi[n]}, AnyTrue[(n - 1)*p, Divisible[#, phi] &]]; Select[carmichaels, q] (* Amiram Eldar, Dec 26 2020 *)
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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