A217646 Periods associated with A217611.

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

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