cyclic numbers: A086018

[Ed Pegg Jr.]

I verify Jud's term 248881.

A method can be seen in the Mathematica documentation under
MultiplicativeOrder.  That leads to the following code:

DigitCycleLength[r_Rational, b_Integer?Positive] := MultiplicativeOrder[b, \
FixedPoint[Quotient[#, GCD[#, b]] &, Denominator[r]]];
a = 0;
Do[If[Prime[n] - DigitCycleLength[1/Prime[n], 10] == 1,
            a++], {n, 2, PrimePi[10^7]}]
Print[a]

For the next term, change 10^7 to 10^8

--Ed Pegg Jr.

Jud McCranie wrote:

> At 06:36 PM 8/29/2003, Jud McCranie wrote:
>
>> At 05:57 PM 8/29/2003, Eric W. Weisstein wrote:
>>
>>> Does anyone know if any further terms are known to
>>>
>>> A086018 0,1,9,60,467,3617,29500
>>
>
>
>
>> Aren't these simply the primes that have 10 as a primitive root?  
>> Then I get 248881 for the next term.
>
>
> And I get 2165288 for the term after that one.  I need to double-check 
> my program though.
>
> Also see A006883 and A001913.
>
>