I saw this formula $$\frac{p_n}{n} < \log n + \log \log n \quad\text{for } n \ge 6$$ on this Wikipedia site https://en.wikipedia.org/wiki/Prime_number_theorem#Non-asymptotic_bounds_on_the_prime-counting_function. I needed a proof so I checked the sources. I couldn't find a proof...
If there is, please tell me on what page and I apologize deeply. If not - please send me a link to a proof.