Combinatorics: How to choose k objects from limited number of choices?
24036
extended stars-and-bars problem(where the upper limit of the variable is bounded)
8173
Number of ways to choose $n$ balls from $3n$ balls, distinguishable/indistinguishable.
21000
Calculating $\sum_{k=1}^nk(k!)$ combinatorially
116626
How to choose between an odd number of options with a fair coin
96086
Double Factorial: Number of possibilities to partition a set of $2n$ items into $n$ pairs
108971
Finding the limit of $\sqrt[n]{{kn \choose n}}$
110856
Number of ways to select $K$ people from $N$ people such that at least $r$ people are there in between them
8149
Algorithm to return all combinations of k elements from n
158285
How to solve this combinatorial problem about selecting letters from different groups?
69827
Set conditions at a permutation
48994
$n$ balls are thrown randomly into $k$ bins - how many are empty?
143132
How to reverse the $n$ choose $k$ formula?
70327
the numer of partial function between two sets in combinatoric way
134440
An unexpected application of non-trivial combinatorics
45074
Combinatorics: Selecting objects arranged in a circle
126583
Coloring points on an n-gon
150536
Combinatorics, choosing 3 elements from 100