number of ways, n can be written as a product of k integers
66989
Divisor function asymptotics
134352
The number of possible factorizations of a positive integer.
3786
Help finding a combinatorial proof of $k {n \choose k } = n {n - 1 \choose k -1}\;$
118674
Simple upper bound for $\binom{n}{k}$
57221
counting the number of elements in a conjugacy class of $S_n$
6366
Combinatorial proof of summation of $\sum\limits_{k = 0}^n {n \choose k}^2= {2n \choose n}$
103347
combinatorial proof of summation
70282
Help finding a combinatorial proof of $k {n \choose k } = n {n - 1 \choose k -1}$
1627
Cartesian product of an arbitrary number of sets
117761
When is $\binom{n}{k}$ divisible by $n$?
142534
Proof of $k {n\choose k} = n {n-1 \choose k-1}$ using direct proof
47799
Show that the number or $r$ combinations of $X$ which contain no consecutive integers is given by $\binom{n-r+1}{r}$
19571
Combinatorial proof for $\sum_{k = 0}^n \binom {r+k} k = \binom {r + n + 1} n$
9411
Number of permutations of $n$ elements where no number $i$ is in position $i$
67927
Combinatorial argument for the identity $k\binom{n}{k} = n\binom{n-1}{k-1}$
24588
Proving the combinatorial identity ${n \choose k} = {n-2\choose k-2} + 2{n-2\choose k-1} + {n-2\choose k}$
67926
$S_n$ is generated by elements of the form $(1k)$