https://www2.math.upenn.edu/~wilf/website/Probabilistic%20proo | Непрерывное математическое образование

https://www2.math.upenn.edu/~wilf/website/Probabilistic%20proof.pdf «Surprisingly, in view of the simplicity of the formula, it is difficult to explain why the hook lengths appear. (…) In the original proof hook lengths appear in the course of rearranging…