How to prove that for all positive integers $n$ $0< \sum_{k=1}^{n}\frac{g(k)}{k}-\frac{2n}{3}<\frac{2}{3}$ where $g(k)$ denotes the greatest odd divisor of $k$
Prove that 0< \sum_{k=1}^{n}g(k)/k-2n/3 < 2/3
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number-theory
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0Have you made any a$t$tempt at the problem yoursel$f$? – 2012-06-27
1 Answers
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Hint: $k/g(k)$ is the greatest power of $2$ dividing $k$.
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0Add up the contributions of $g(k)/k=1, 1/2, 1/4, \ldots$, which are at most $(n+1)/2, (n+2)/8, (n+4)/16, \ldots$. What do you get? – 2012-06-27