English

Connections between two classes of generalized Fibonacci numbers squared and permanents of (0,1) Toeplitz matrices

Combinatorics 2024-09-04 v1

Abstract

By considering the tiling of an NN-board (a linear array of NN square cells of unit width) with new types of tile that we refer to as combs, we give a combinatorial interpretation of the product of two consecutive generalized Fibonacci numbers sns_n (where sn=i=1qvisnmis_{n}=\sum_{i=1}^q v_i s_{n-m_i}, s0=1s_0=1, sn<0=0s_{n<0}=0, where viv_i and mim_i are positive integers and m1<<mqm_1<\cdots<m_q) each raised to an arbitrary non-negative integer power. A (w,g;m)(w,g;m)-comb is a tile composed of mm rectangular sub-tiles of dimensions w×1w\times1 separated by gaps of width gg. The interpretation is used to give combinatorial proof of new convolution-type identities relating sn2s_n^2 for the cases q=2q=2, vi=1v_i=1, m1=Mm_1=M, m2=m+1m_2=m+1 for M=0,mM=0,m to the permanent of a (0,1) Toeplitz matrix with 3 nonzero diagonals which are 2-2, M1M-1, and mm above the leading diagonal. When m=1m=1 these identities reduce to ones connecting the Padovan and Narayana's cows numbers.

Keywords

Cite

@article{arxiv.2107.02589,
  title  = {Connections between two classes of generalized Fibonacci numbers squared and permanents of (0,1) Toeplitz matrices},
  author = {Michael A. Allen and Kenneth Edwards},
  journal= {arXiv preprint arXiv:2107.02589},
  year   = {2024}
}

Comments

10 pages, 5 figures