Counting the number of products that can be formed from an ordered n-tuple
57058
Number of ways to insert parentheses between elements
117862
Number of partitions of an $n$-element set into $k$ classes
27273
Count the number of topological sorts for poset (A|)?
57221
counting the number of elements in a conjugacy class of $S_n$
101751
The number of words that can be made by permuting the letters of _MATHEMATICS_ is
127233
Cardinality of order types in $\mathbb{N}$
96169
$n$ divides a product of $n$ consecutive integers (by $n$ divides one of them)
67451
Building a bijection from a finite union of countable sets to $\mathbb{N}$
20095
How to extract the n-th elements from a list of tuples?
37012
The number of summands $\phi(n)$
44214
The number of subsets of a set of cardinality $n$
116251
Number of distinct total orders on a set
26569
Counting binary operations on a set with $n$ elements
112188
Duplicate Permutations with Tuples
97314
Counting nearly-sorted permutations
60416
Finding a permutation, and number of, from powers of the permutation
155777
Show that infinite Cartesian product is uncountable