Biunitary Divisor

A divisor  of a positive integer  is biunitary if the greatest common unitary divisor of  and  is 1. For a prime power , the biunitary divisors are the powers 1, , , ..., , except for  when  is even (Cohen 1990).

REFERENCES:

Cohen, G. L. "On an Integer's Infinitary Divisors." Math. Comput. 54, 395-411, 1990.

Suryanarayana, D. "The Number of Bi-Unitary Divisors of an Integer." The Theory of Arithmetic Functions (Proc. Conf., Western Michigan Univ., Kalamazoo, Mich., 1971. New York: Springer-Verlag, pp. 273-282, 1972.

Suryanarayana, D. and Rao, R. S. R. C. "The Number of Bi-Unitary Divisors of an Integer. II." J. Indian Math. Soc. 39, 261-280, 1975.