Front representation of set partitions
Combinatorics
2011-08-30 v3
Abstract
Let be a set partition of . The standard representation of is the graph on the vertex set whose edges are the pairs of integers with in the same block which does not contain any integer between and . The front representation of is the graph on the vertex set whose edges are the pairs of integers with in the same block whose smallest integer is . Using the front representation, we find a recurrence relation for the number of -avoiding partitions for . Similarly, we find a recurrence relation for the number of -distant noncrossing partitions for . We also prove that the front representation has several joint symmetric distributions for crossings and nestings as the standard representation does.
Cite
@article{arxiv.0907.1485,
title = {Front representation of set partitions},
author = {Jang Soo Kim},
journal= {arXiv preprint arXiv:0907.1485},
year = {2011}
}
Comments
16 pages, 7 figures, final version