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A056217 Primes p for which the period of reciprocal 1/p is (p-1)/12. 7
37, 613, 733, 1597, 2677, 3037, 4957, 5197, 5641, 7129, 7333, 7573, 8521, 8677, 11317, 14281, 14293, 15289, 15373, 16249, 17053, 17293, 17317, 19441, 20161, 21397, 21613, 21997, 23053, 23197, 24133, 25357, 25717, 26053, 26293, 27277 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Cyclic numbers of the twelfth degree (or twelfth order): the reciprocals of these numbers belong to one of twelve different cycles. Each cycle has the (number minus 1)/12 digits.

LINKS

Index entries for sequences related to decimal expansion of 1/n

MATHEMATICA

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, 3000]], f[ # ] == 12 &]

CROSSREFS

Sequence in context: A006303 A156226 A133998 * A105464 A140764 A156923

Adjacent sequences:  A056214 A056215 A056216 * A056218 A056219 A056220

KEYWORD

nonn,base

AUTHOR

Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 02 2000

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Last modified February 15 14:54 EST 2012. Contains 205822 sequences.