Published online by Cambridge University Press: 09 April 2009
It is known that a divisor d>0 of the positive integer n is called unitary [3;§ 1] if dδ = n and (d, δ) = 1, where (d, δ) denotes the g.c.d. of d and δ. We write d¶. Let k be a fixed positive integer. A positve integer n is called k-free if n is not divisible by the kth power of any prime.