enumerate the number of perfect matchings in directed complete graphs?
54749
How to find the number of perfect matchings in complete graphs?
3217
Construction of uncountably many non-isomorphic linear (total) orderings of natural numbers
111345
Best algorithm for detecting cycles in a directed graph
115085
number of vertices in a self-complemntary graph
17086
The number of (non-equal) forests on the vertex set V = {1, 2, ...,n} that contains exactly 2 connected components is given by
138226
Finding All n-regular graphs on m vertices
58508
Number of ways to pair off $2n$ points such that no chords intersect
49879
A bipartite graph with a perfect matching has a vertex with each edge contained in a perfect matching
85541
What is the maximum length of a circuit in the complete graph on n vertices.
47240
An alternate solution to the hat-matching problem, probability of exactly $k$ matches
61136
How to find all graph isomorphisms in FindGraphIsomorphism
120684
Calculating the number of possible paths through some squares
26569
Counting binary operations on a set with $n$ elements
62175
A general formula for $n$ distinguishable arrangements of length $\ell$ of a sequence of a given size?
99806
Given an undirected Graph
97314
Counting nearly-sorted permutations
89611
Combinations of selecting $n$ objects with $k$ different types