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A056212
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Primes p whose period of reciprocal equals (p-1)/7.
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12
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211, 617, 1499, 2087, 2857, 6007, 6469, 7127, 7211, 7589, 9661, 10193, 13259, 13553, 14771, 18047, 18257, 19937, 20903, 21379, 23549, 26153, 27259, 27539, 32299, 33181, 33461, 34847, 35491, 35897, 41651, 42407, 42491, 43051, 43793
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OFFSET
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1,1
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COMMENTS
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Cyclic numbers of the seventh degree (or seventh order): the reciprocals of these numbers belong to one of seven different cycles. Each cycle has the (number minus 1)/7 digits.
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LINKS
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MATHEMATICA
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f[n_Integer] := Block[{ds = Divisors[n - 1]}, (n - 1)/Take[ ds, Position[ PowerMod[ 10, ds, n], 1] [[1, 1]]] [[ -1]]]; Select[ Prime[ Range[4, 4700]], f[ # ] == 7 &]
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CROSSREFS
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Cf. A097443, A055628, A056157, A056210, A056211, A056213, A056214, A056215, A056216, A056217, A098680, A135073.
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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