Permutations with categories (Multinomial Coefficients): formula proof
97254
What is the proof of permutations of similar objects?
106008
Combinatorial Identity $(n-r) \binom{n+r-1}{r} \binom{n}{r} = n \binom{n+r-1}{2r} \binom{2r}{r}$
108742
Proving commutativity of addition for vector spaces
44480
Let $\sigma :\{1,2,3,4,5\} \rightarrow \{1,2,3,4,5\}$ be permutations such that $ \sigma^{-1}(j) \leq \sigma(j)~\forall j, 1 \leq j \leq 5$.
4555
How to write permutations as product of disjoint cycles and transpositions
46036
Logic for decomposing a permutation into different products composed of transpositions
113953
Circular permutations with indistinguishable objects
54794
British Olympiad; Combinatorics Recursion
19571
Combinatorial proof for $\sum_{k = 0}^n \binom {r+k} k = \binom {r + n + 1} n$
101751
The number of words that can be made by permuting the letters of _MATHEMATICS_ is
20636
Algorithm for finding numerical permutation given lexicographic index
149609
Conditions on cycle types for permutations to generate $S_n$
128966
Explicit bijection between $\Bbb R$ and permutations of $\Bbb N$
115209
Elementary formula for permutations?
90904
Combinatorial proof of an identity with squared binomial coefficients
8627
Number of equivalence classes of $w \times h$ matrices under switching rows and columns
39724
Combinatorial Identities