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A217646 Periods associated with A217611. 1
2, 1, 6, 3, 18, 9, 30, 42, 78, 114, 138, 87, 330, 318, 189, 462, 408, 504, 303, 561, 1002, 2040, 1794, 1746, 2418, 2790, 1389, 3894, 4722, 6738, 4077, 14610, 14616, 15294, 16662, 18966, 10641, 27144, 26142, 39360, 31638 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..41.

EXAMPLE

The octal expansion of 1/73 is 0.007007..., having a period of 3 and it is the only prime with that period.

MATHEMATICA

lst1 = {}; lst2 = {}; lst4 = {}; Do[c = Cyclotomic[n, 8]; q = c/GCD[n, c]; If[PrimePowerQ[q], p = FactorInteger[q][[1, 1]]; AppendTo[lst1, p]; AppendTo[lst2, n]], {n, 561}]; lst3 = Sort[lst1]; Do[AppendTo[lst4, Take[lst2, Flatten@Position[lst1, lst3[[p]]]]], {p, Length@lst3}]; Flatten[lst4]

CROSSREFS

Cf. A217611.

Sequence in context: A131174 A291539 A135994 * A133166 A293409 A051482

Adjacent sequences:  A217643 A217644 A217645 * A217647 A217648 A217649

KEYWORD

base,nonn

AUTHOR

Arkadiusz Wesolowski, Oct 09 2012

STATUS

approved

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Last modified September 27 16:20 EDT 2020. Contains 337383 sequences. (Running on oeis4.)