All Questions
Tagged with catalan-numbers graph-theory
4 questions
12
votes
1
answer
509
views
Probability of a graph procedure
We are going to build $K_n$ one edge at a time. Begin with the empty graph on $n$ vertices. Take a random permutation of the edges of $K_n$ and, one at a time, place the edges onto the graph (so, ...
6
votes
0
answers
295
views
Catalan numbers from matchings?
There are several examples of interpreting the Catalan numbers as non-nesting or non-crossing matchings of some graph.
My question is:
Is there a family of graphs $G_1,G_2,\dotsc$ with the number of ...
4
votes
0
answers
208
views
More 3-connected cubic graphs with all 2-factors of same cycle type?
The setup is as in this question: Let $G$ be a 3-connected cubic graph. If all 2-factors of $G$ are isomorphic (as graphs), i.e. all have the same partition $\pi$ as cycle type, we'll say that $G$ is ...
2
votes
0
answers
235
views
Injection of Catalan objects into 3-connected planar graphs
Let $C_n = \frac{1}{n+1}\binom{2n}{n}$ be the $n$-th Catalan number, counting, for example, the number of (rooted) triangulations of the $(n+2)$-gon.
Let $P_n$ be the number of three-connected planar ...