English

Relationship between Vieta-Lucas polynomials and Lucas sequences

Number Theory 2022-12-16 v1

Abstract

Let wn=wn(P,Q)w_n=w_n(P,Q) be numerical sequences which satisfy the recursion relation \begin{equation*} w_{n+2}=Pw_{n+1}-Qw_n. \end{equation*} We consider two special cases (w0,w1)=(0,1)(w_0,w_1)=(0,1) and (w0,w1)=(2,P)(w_0,w_1)=(2,P) and we denote them by UnU_n and VnV_n respectively. Vieta-Lucas polynomial Vn(X,1)V_n(X,1) is the polynomial of degree nn. We show that the congruence equation Vn(X,1)CmodpV_n(X,1)\equiv C \mod p has a solution if and only if U(pϵ)/d(C+2,C+2)U_{(p-\epsilon)/d}(C+2,C+2) is divisible by pp, where ϵ{±1}\epsilon\in\{\pm 1\} depends on CC and pp, and d=gcd(n,pϵ)d=\gcd(n,p-\epsilon).

Cite

@article{arxiv.2212.07690,
  title  = {Relationship between Vieta-Lucas polynomials and Lucas sequences},
  author = {Futa Matsumoto},
  journal= {arXiv preprint arXiv:2212.07690},
  year   = {2022}
}

Comments

9 pages

R2 v1 2026-06-28T07:36:00.801Z