Problem

Source:

Tags: number theory, 5th edition



For any positive integer $n$, let $s(n)$ be the sum of its digits, written in decimal base. Prove that for each integer $n \ge 1$ there exists a positive integer $x$ such that the fraction $\frac{x + k}{s(x + k)}$ is not integral, for each integer $k$ with $0 \le k \le n$.