I'm reading this paper which says
If we have
$ \binom n d p^{\binom d 2} = 1 $
where $ 0 < p \le 1$, then
$ d = 2 \log_bn - 2 \log_b \log_b n + 2 \log_b\left(\frac 1 2 e\right) + 1 + O(1) $
where $b = \frac 1 p$.
As the authors skimmed the proof, I've completely no idea how they reached the conclusion.