The Möbius function

Corollary

Let - words which the length is equal to n, then

, ,
, ,

So, if length is equal to n=4, there are 24 words from 81 with different cycles.

References

1.BERKELEY MATH CIRCLE 1998-99

2.	I.M. Vinogradov, "Elements of number theory", Dover, reprint (1954) (Translated from Russian) MR0062138 3. Б. М. Веретенников м. М. Михалева Aлгебра и теория чисел

(Dilafruz Sh.Usmonova)

National University (Mirzo Ulugbek)

of Uzbekistan, 100174 Tashkent, Uzbekistan

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