English

On determinants involving second-order recurrent sequences

Number Theory 2023-02-21 v2 Combinatorics

Abstract

Let AA and BB be complex numbers, and let (wn)n0(w_n)_{n\ge0} be a sequence of complex numbers with wn+1=AwnBwn1w_{n+1}=Aw_n-Bw_{n-1} for all n=1,2,3,n=1,2,3,\ldots. When w0=0w_0=0 and w1=1w_1=1, the sequence (wn)n0(w_n)_{n\ge0} is just the Lucas sequence (un(A,B))n0(u_n(A,B))_{n\ge0}. In this paper, we evaluate the determinants det[wjk]1j,kn  and  det[wjk+1]1j,kn.\det[w_{|j-k|}]_{1\le j,k\le n}\ \ \text{and}\ \ \det[w_{|j-k+1|}]_{1\le j,k\le n}. In particular, we have det[ujk(A,B)]1j,kn=(1)n1un1(2A,(B+1)2).\det[u_{|j-k|}(A,B)]_{1\le j,k\le n}=(-1)^{n-1}u_{n-1}(2A,(B+1)^2). When B=1B=-1 and 2n2\mid n, we also determine the characteristic polynomial of the matrix [wj+k]0j,kn1[w_{j+k}]_{0\le j,k\le n-1}.

Keywords

Cite

@article{arxiv.2302.08315,
  title  = {On determinants involving second-order recurrent sequences},
  author = {Zhi-Wei Sun},
  journal= {arXiv preprint arXiv:2302.08315},
  year   = {2023}
}

Comments

14 pages. Add Theorems 1.3 and 1.4

R2 v1 2026-06-28T08:41:51.795Z