Let a Divisor of be called a 1-ary divisor if . Then is called a -ary divisor of , written , if the Greatest Common -ary divisor of and is 1.
In this notation, is written , and is written . is an Infinary Divisor of (with ) if .
See also Divisor, Greatest Common Divisor, Infinary Divisor
References
Guy, R. K. Unsolved Problems in Number Theory, 2nd ed. New York: Springer-Verlag, p. 54, 1994.