Combinatorics and Catalan Numbers
40467
Intuition behind Hook Length Formula
85668
Very elementary number theory and combinatorics books.
110723
Catalan numbers and triangulation
40763
Possible orders of permutations of $11$ symbols
107021
Finding a combinatorial argument for an interesting identity: $\sum_k \binom nk \binom{m+k}n = \sum_i \binom ni \binom mi 2^i$
45204
Combinatorial proofs: having a difficult time understanding how to write them out
17580
Combinatorics That Looks Similar to Vandermonde's Identity
42062
Interpretation of a combinatorial expression
23322
Combinatorics Inclusion - Exclusion Principle
122504
Factorisations of permutations
41205
Help me solve a combinatorial problem
44454
Rooted Binary Trees and Catalan Numbers
89552
proving combinatorics identity - $\sum_{k=0}^m{n-k \choose m-k}={n+1 \choose m}$
76635
Proof through combinatorial argument
58103
number of permutations in which no two consecutive numbers are adjacent
14986
Proving a combinatorics equality: $\binom{r}{r} + \binom{r+1}{r} + \cdots + \binom{n}{r} = \binom{n+1}{r+1}$
107964
Simple combinatorics problem.