Question 25
Let $S(k)$ denote the sum of digits (in base 10) of any positive integer $k$. Does there exist a positive integer $N$ so that $S(2^n) \le S(2^{n+1})$ for all integers $n \gt N$?
Math Olympiad Vault · MathNet 2023-part-03 — 191 problems (EN–VI)