K balls in N boxes, no boxes contain 1 ball
141435
probability of $k$ boxes contain exactly $1$ ball
10939
Probability that a k digit number does not contain certain digits
85225
The set of integers is not open or is open
9739
Placing $9$ black and $9$ white rooks on $ 6\times6$ board without any attacks between different colours
72468
Open and closed balls in $C[a,b]$
52594
Can all circles of radius $1/n$ be packed in a unit disk, excluding the circle of radius $1/1$?
70282
Help finding a combinatorial proof of $k {n \choose k } = n {n - 1 \choose k -1}$
148776
A different approach in distributing $8$ distinct balls into $6$ distinct boxes
117862
Number of partitions of an $n$-element set into $k$ classes
43076
Chess tournament combinatorics
102250
Subset of $C[0,1]$ is nowhere dense
107448
proving that there is no solution for $n$ in positive integers except $n = 1$ for $2^n = nk + 1$
4041
Claims and questions regarding $n$-ball distribution?
143132
How to reverse the $n$ choose $k$ formula?
153305
Adding subsets of regular cardinals (Jech p. 226)
53179
Combinations, when placing n objects into k boxes, each box has its own size and the order in them doesn't matter?
67817
Number of ways to distribute 5 distinguishable balls between 3 kids such that each of them gets at least one ball