English

A Recursion for the FiboNarayana and the Generalized Narayana Numbers

Combinatorics 2019-10-22 v1

Abstract

The Lucas polynomials, {n}\{n\}, are polynomials in ss and tt given by {n}=s{n1}+t{n2}\{ n \} = s \{ n-1 \} + t \{ n-2 \} for n2n \geq 2 with {0}=0 \{ 0 \} = 0 and {1}=1\{ 1 \} = 1. The lucanomial coefficients, an analogue of the binomial coefficients, are given by {nk}={n}!{k}!{nk}!. \Bigl\{ \begin{array}{c} n\\k \end{array} \Bigr \} = \frac{ \{n\}! }{ \{k\}! \{n-k\}!}. When s=t=1s = t = 1 then {n}=Fn\{ n \} = F_n and the lucanomial coefficient becomes the fibonomial coefficient (nk)F=Fn!Fk!Fnk!. \binom{n}{k}_F = \frac{F_n!}{F_k! F_{n-k}!}. The well-known Narayana numbers, Nn,kN_{n,k} satisfy the equation Nn,k=1n(nk)(nk1). N_{n,k} = \frac{1}{n} \binom{n}{k} \binom{n}{k-1}. %C_n = \sum_{k=1}^n N_{n,k}. % In 2018, Bennett, Carrillo, Machacek and Sagan defined the generalized Narayana numbers and conjectured that these numbers are positive integers for n1n \geq 1. In this paper we define the FiboNarayana number Nn,k,FN_{n,k,F} and give a new recurrence relation for both the FiboNarayana numbers and the generalized Narayana numbers, proving the conjecture that these are positive integers for n1n \geq 1.

Keywords

Cite

@article{arxiv.1910.08855,
  title  = {A Recursion for the FiboNarayana and the Generalized Narayana Numbers},
  author = {Kristina Garrett and Kendra Killpatrick},
  journal= {arXiv preprint arXiv:1910.08855},
  year   = {2019}
}