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Search: id:A056210
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| A056210 |
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Primes p for which the period of reciprocal = (p-1)/5. |
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+0
7
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| 11, 251, 1061, 1451, 1901, 1931, 2381, 3181, 3491, 3851, 4621, 4861, 5261, 6101, 6491, 6581, 6781, 7331, 8101, 9941, 10331, 10771, 11251, 11261, 11411, 12301, 14051, 14221, 14411, 15091, 15131, 16061, 16141, 16301, 16651, 16811, 16901
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OFFSET
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1,1
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COMMENT
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Cyclic numbers of the fifth degree (or fifth order): the reciprocals of these numbers belong to one of five different cycles. Each cycle has the (number minus 1)/5 digits.
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LINKS
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T. D. Noe, Table of n, a(n) for n=1..1000
Index entries for sequences related to decimal expansion of 1/n
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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, 2000]], f[ # ] == 5 &]
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CROSSREFS
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Cf. A001913, A097443, A055628, A056157, A056211-A056217, A098680
Sequence in context: A041223 A041220 A098672 this_sequence A089298 A012154 A009055
Adjacent sequences: A056207 A056208 A056209 this_sequence A056211 A056212 A056213
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KEYWORD
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nonn
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AUTHOR
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Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 02 2000
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EXTENSIONS
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Entry revised by N. J. A. Sloane (njas(AT)research.att.com), Apr 30 2007
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