An integer n is said to be square-free if no perfect square (other than 1) divides n. Similarly, n is said to be cube-free if no perfect cube (other than 1) divides n. In general, n is said to be k-free if it has no divisor d > 1 where d is a kth power […] The post Density of square-free numbers, cube-free numbers, etc. first appeared on John D. Cook....