English

New combinatorial interpretations of the binomial coefficients

Combinatorics 2019-04-01 v3

Abstract

Using generating functions and some trivial bijections, we show in this paper that the binomial coefficients count the set of (123,132) and (123,213)-avoiding permutations according to the number of crossings. We also define a q-tableau of power of two and prove that it counts the set of (213,312) and (132,312)-avoiding permutations according to the number of crossings.

Keywords

Cite

@article{arxiv.1903.06589,
  title  = {New combinatorial interpretations of the binomial coefficients},
  author = {Paul M. Rakotomamonjy and Sandrataniaina R. Andriantsoa},
  journal= {arXiv preprint arXiv:1903.06589},
  year   = {2019}
}

Comments

15 pages, 2 figures and 1 table

R2 v1 2026-06-23T08:09:29.371Z