English

A note on 2-distant noncrossing partitions and weighted Motzkin paths

Combinatorics 2010-11-03 v2

Abstract

We prove a conjecture of Drake and Kim: the number of 22-distant noncrossing partitions of {1,2,...,n}\{1,2,...,n\} is equal to the sum of weights of Motzkin paths of length nn, where the weight of a Motzkin path is a product of certain fractions involving Fibonacci numbers. We provide two proofs of their conjecture: one uses continued fractions and the other is combinatorial.

Keywords

Cite

@article{arxiv.1003.5301,
  title  = {A note on 2-distant noncrossing partitions and weighted Motzkin paths},
  author = {Ira M. Gessel and Jang Soo Kim},
  journal= {arXiv preprint arXiv:1003.5301},
  year   = {2010}
}

Comments

6 pages, 2 figures

R2 v1 2026-06-21T15:03:24.234Z