New posts in combinatorial-proofs

Combinatorial Proof for $\sum_{k=0}^n \binom{2n}{2k}^2 = \frac{1}{2}\left( \binom{4n}{2n}+(-1)^n \binom{2n}{n} \right)$

combinatorics summation binomial-coefficients combinatorial-proofs

Combinatorics meaning of $L_m=\sum_{j=m}^{n}(-1)^{j-m}\binom{j-1}{m-1}S_j$

combinatorics inclusion-exclusion combinatorial-proofs

More elegant proofs of $\binom a2+\binom b2\leq \binom{a+b-1}2$

combinatorics inequality binomial-coefficients combinatorial-proofs extremal-combinatorics

Combinatorial proof $\sum_i^{\lfloor{n/2}\rfloor} (-1)^i {n-i\choose i} 2^{n-2i} = n+1$

combinatorics combinations combinatorial-proofs

Combinatorial justification on $n^{2} = (n-1)^{2} + 2(n-1) +1$

discrete-mathematics combinatorial-proofs

Combinatorial proof of $\binom{nk}{2}=k\binom{n}{2}+n^2\binom{k}{2}$

combinatorics discrete-mathematics binomial-coefficients combinatorial-proofs

Stirling numbers combinatorial proof

combinatorics discrete-mathematics inclusion-exclusion combinatorial-proofs stirling-numbers

Can this be proved using Combinatorics or generating functions?

combinatorics summation binomial-coefficients generating-functions combinatorial-proofs

Help with combinatorial proof of identity: $\sum_{k=1}^{n} \frac{(-1)^{k+1}}{k} \binom{n}{k} = \sum_{k=1}^{n} \frac{1}{k}$

sequences-and-series combinatorics discrete-mathematics binomial-coefficients combinatorial-proofs

Non-crossing partitions without singletons

combinatorics recurrence-relations combinatorial-proofs catalan-numbers

A combinatorial proof of the identity: $\sum_{k=1}^n k \binom{n}{k}^2 = {n}\binom{2n-1}{n-1}$?

combinatorics summation permutations combinations combinatorial-proofs

Bijection between perfect matchings permutations with even cycles

combinatorics combinatorial-proofs combinatorial-species

On a combinatorial identity involving elementary symmetric polynomials

combinatorics combinatorial-proofs

combinatorial proof of summation

combinatorics discrete-mathematics summation combinatorial-proofs

proving $\binom{n-1}{k} - \binom{n-1}{k-2} = \binom{n}{k} - \binom{n}{k-1} $

combinatorics binomial-coefficients combinatorial-proofs

$\sum_{i=k}^{z} \frac{(-1)^{i-k} {z\choose i}{i\choose k}}{i+1} = \frac{1}{z+1} ​$ - combinatorial identity

integration combinatorics combinatorial-proofs

Combi Problem - Proving Existence of a row

combinatorics contest-math pigeonhole-principle combinatorial-proofs

Length of continued fractions

combinatorics prime-numbers continued-fractions combinatorial-proofs

The following combinatorial equality is true? If yes, anyone can give me a hint how to prove it?

probability combinatorics discrete-mathematics combinations combinatorial-proofs

Does the functional equation $p(x^2)=p(x)p(x+1)$ have a combinatorial interpretation?

combinatorics polynomials generating-functions alternative-proof combinatorial-proofs