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A051627 Periods associated with A040017. 6
1, 2, 3, 4, 10, 12, 9, 14, 24, 36, 48, 38, 19, 23, 39, 62, 120, 150, 106, 93, 134, 294, 196, 320, 654, 738, 385, 586, 317, 597, 1404, 945, 1452, 1836, 1752, 1172, 1812, 1282, 1426, 2232, 1862, 1844, 1521, 2134, 3750, 1031, 2264, 2667, 4354, 3927, 4274, 6522, 3903, 6022, 6682, 6135, 9550, 5877 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
The numbers in A007498 sorted according to the magnitude of the corresponding prime. - T. D. Noe, Sep 08 2005
LINKS
C. K. Caldwell, Unique Primes
Eric Weisstein's World of Mathematics, Unique Prime
FORMULA
a(n) = A002371(A000720(A040017(n))). - Max Alekseyev, Oct 14 2022
EXAMPLE
The decimal expansion of 1/101 is 0.00990099..., having a period of 4 and it is the only prime with that period.
MATHEMATICA
nmax = 10000; primesPeriods = Reap[Do[p = Cyclotomic[n, 10]/GCD[n, Cyclotomic[n, 10]]; If[PrimeQ[p], Print[n]; Sow[{p, n}]], {n, 1, nmax}]][[2, 1]]; Sort[primesPeriods][[All, 2]] // Prepend[#, 1]& // Take[#, 58]& (* Jean-François Alcover, Mar 29 2013 *)
CROSSREFS
Sequence in context: A087460 A082866 A085701 * A023725 A250051 A076079
KEYWORD
nonn,nice,base
AUTHOR
EXTENSIONS
More terms from Jud McCranie
More terms from T. D. Noe, Sep 08 2005
Corrected a(45)=3750 and extended by Ray Chandler, Oct 13 2008
STATUS
approved

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Last modified March 19 04:58 EDT 2024. Contains 370952 sequences. (Running on oeis4.)