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The period of the decimal fraction 1/A197225(n).
2

%I #9 Oct 25 2019 15:31:04

%S 1,2,16,3,5,13,8,13,41,4,53,8,81,43,113,7,256,5,79,173,32,179,32,233,

%T 239,281,293,32,107,359,61,125,27,193,199,419,151,103,593,41,641,653,

%U 659,32,719,373,761,271,409,313,953,331,1013,1019,137,619,223,31

%N The period of the decimal fraction 1/A197225(n).

%C These numbers are prime powers, members of A000961.

%H Ray Chandler, <a href="/A197226/b197226.txt">Table of n, a(n) for n = 1..1000</a>

%t myPerfectPowerQ[n_] := Length[FactorInteger[n]] == 1; t=Select[Prime[Range[500]], Mod[10,#] > 0 && myPerfectPowerQ[Length[RealDigits[1/#, 10][[1,1]]]] &]; Table[Length[RealDigits[1/n, 10][[1,1]]], {n, t}]

%K nonn,base

%O 1,2

%A _T. D. Noe_, Oct 22 2011