Question 70
Let $\ell(n)$ denote the greatest odd factor of any natural number $n$. Find the sum
$$ \ell(1) + \ell(2) + \ell(3) + \cdots + \ell(2^{2015}). $$
$$ \ell(1) + \ell(2) + \ell(3) + \cdots + \ell(2^{2015}). $$
MathNet 2015-part-03 — 191 problems (EN–VI) Question 70
Math Olympiad Vault · MathNet 2015-part-03 — 191 problems (EN–VI)