Search Results
| Search type | Search syntax |
|---|---|
| Tags | [tag] |
| Exact | "words here" |
| Author |
user:1234 user:me (yours) |
| Score |
score:3 (3+) score:0 (none) |
| Answers |
answers:3 (3+) answers:0 (none) isaccepted:yes hasaccepted:no inquestion:1234 |
| Views | views:250 |
| Code | code:"if (foo != bar)" |
| Sections |
title:apples body:"apples oranges" |
| URL | url:"*.example.com" |
| Saves | in:saves |
| Status |
closed:yes duplicate:no migrated:no wiki:no |
| Types |
is:question is:answer |
| Exclude |
-[tag] -apples |
| For more details on advanced search visit our help page | |
Results tagged with enumerative-combinatorics
Search options not deleted
user 2672
0
votes
Number of permutations with a specified number of fixed points
see Subfactorial or rencontres numbers, or derangements: number of permutations of n elements with no fixed points
12
votes
5
answers
13k
views
Number of permutations with a specified number of fixed points
Let $F(k,n)$ be the number of permutations of an n-element set that fix exactly $k$ elements.
We know:
$F(n,n) = 1$
$F(n-1,n) = 0$
$F(n-2,n) = \binom {n} {2}$
...
$F(0,n) = n! \cdot \sum_{k=0}^n \ …
- 9,720
2
votes
0
answers
168
views
Enumeration and encoding of simplicial complexes
I'd like to know how to enumerate and encode all (abstract) simplicial complexes of a given kind.
To start as simple as possible, consider the familiy $\mathcal{S}_n^{d}$ of simplicial complexes which …
- 9,720