Of the books that have already been mentioned, I like Graham, Knuth, & Patashnik, Concrete Mathematics, isn’t precisely a book on combinatorics, but it offers an excellent treatment of …

I was looking through practice questions and need some guidance/assistance in Fermat's combinatorial identity. I read through this on the stack exchange, but the question was …

Aug 6, 2020 · Can anyone recommend me an olympiad style combinatorics book which is suitable for a high schooler ? I know only some basics like Pigeon hole principle and stars and bars . I …

Is there a comprehensive resource listing binomial identities? I am more interested in combinatorial proofs of such identities, but even a list without proofs will do.

Jan 11, 2016 · Using combinatorial proof is usually a much better approach though to remember many identities like the hockey-stick identity or Vandermonde Identity.

Let me add one purely-combinatorial proof. : the justification for doing so is that I think we can tell this in a "committee-forming" way that is used for other identities (e.g. Pascal's rule), without …

Personally, I see "combinatorics" as the "art of counting", which implies that the underlying objects are at least countable (= discrete), but better finite. I find it natural that "graph theory" is filed …

Oct 30, 2025 · Is there any combinatorial interpretation of this observation? Can we come up with a combinatorial proof of $\text { (*)}$? Although I'd like to provide some motivations or ideas if I …

Do you know any good book that deals extensively with identities obtained using combinatorial and/or probabilistic arguments (e.g., by solving the same combinatorial or probability problem …

Nov 13, 2023 · I think I don't agree on group theory. There are quite a few combinatorial aspects. Permutations and group actions are at the core of combinatorics, the latter one for being the …