Kempner function
= Kempner function
{wiki=Kempner_function}
The Kempner function, often denoted as \\( K(n) \\), is a function defined in number theory that counts the number of positive integers up to \\( n \\) that are relatively prime to \\( n \\) and also which contain no digit equal to 0 when expressed in decimal notation. This function is named after mathematician Howard Kempner. More formally, the Kempner function can be defined as follows: - Let \\( n \\) be a positive integer.