New posts in combinatorial-proofs

Prove using combinatorics $n \mid \binom{n}{m} \binom{n}{m-1}$

combinatorics combinatorial-proofs

Combinatorial interpretation of a sum identity: $\sum_{k=1}^n(k-1)(n-k)=\binom{n}{3}$

combinatorics summation combinatorial-proofs

How should I solve combination addition like this?

combinatorics summation combinations binomial-coefficients combinatorial-proofs

Do you know the website of the journal Ars Combinatoria?

combinatorics combinations combinatorial-proofs combinatorial-game-theory combinatorial-geometry

Combinatorial intuition of identity

combinatorics combinations combinatorial-proofs

Prove by Combinatorial Argument that $\binom{n}{k}= \frac{n}{k} \binom{n-1}{k-1}$

combinatorics binomial-coefficients combinatorial-proofs

A recurrence for the number of non-crossing partitions without singletons, using Dyck paths

combinatorics discrete-mathematics combinatorial-proofs set-partition catalan-numbers

Combinatorial Identity $(n-r) \binom{n+r-1}{r} \binom{n}{r} = n \binom{n+r-1}{2r} \binom{2r}{r}$

combinatorics binomial-coefficients combinatorial-proofs

Combinatorial proof of the identity $3^n=\sum_{k=0}^n \binom nk 2^k$

combinatorics summation binomial-coefficients combinatorial-proofs

Prove $1^2+2^2+\cdots+n^2 = {n+1\choose2}+2{n+1\choose3}$

combinatorics summation combinatorial-proofs

Coefficient of $\frac{1}{1-x-x^2-..-x^{d-1}}$ and its asymptotic

combinatorics asymptotics recurrence-relations generating-functions combinatorial-proofs

Combinatorial proofs of the following identities

combinatorics discrete-mathematics combinatorial-proofs

Combinatorial identity from squaring the binomial expansion

combinatorics binomial-coefficients binomial-theorem combinatorial-proofs

A congruence in the number of certain ternary strings

combinatorics elementary-number-theory recreational-mathematics combinatorial-proofs

Is there an explicit construction of this bijection?

combinatorics combinatorial-proofs

Combinatorial Proof of $\binom{\binom{n}{2}}{2} = 3 \binom{n}{3}+ 3 \binom{n}{4}$ for $n \geq 4$

combinatorics binomial-coefficients combinatorial-proofs

Strange combinatorial identity $\sum_{k=0}^{n}(-1)^{k}\binom{n}{k}\binom{2n-2k}{n-1}=0$ [duplicate]

combinatorics combinatorial-proofs

Combinatorial explanation for why $n^2 = {n \choose 2} + {n+1 \choose 2}$

combinatorics discrete-mathematics binomial-coefficients combinatorial-proofs

Find the generating function of $f(n) = \sum_{k = 0}^n \binom{n}{k} (-1)^{n-k}C_{k}$

combinatorics discrete-mathematics generating-functions combinatorial-proofs catalan-numbers

Prove by Double Counting Method $\sum\limits_{k = 0}^m \binom{m}{k}\binom{n}{r + k} = \binom{m + n}{m + r}$ [duplicate]

combinatorics summation permutations binomial-coefficients combinatorial-proofs