How to prove that $ \sum_{n=1}^{\infty} \frac{(-1)^{[\log n]}}{n}$ diverges?

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How to prove that $\sum_{n=1}^{\infty} \frac{(-1)^{[\log n]}}{n}$ diverges? I've tried something with the following $$\log n - 1 <[\log n] \leq \log n$$ but I haven't got anything from that. Can someone give me a hint?