English

Strong arithmetic property of certain Stern polynomials

Number Theory 2019-09-25 v1

Abstract

Let Bn(t)B_{n}(t) be the nnth Stern polynomial, i.e., the nnth term of the sequence defined recursively as B0(t)=0,B1(t)=1B_{0}(t)=0, B_{1}(t)=1 and B2n(t)=tBn(t),B2n+1(t)=Bn(t)+Bn1(t)B_{2n}(t)=tB_{n}(t), B_{2n+1}(t)=B_{n}(t)+B_{n-1}(t) for nNn\in\N. It is well know that iith coefficient in the polynomial Bn(t)B_{n}(t) counts the number of hyperbinary representations of n1n-1 containing exactly ii digits 1. In this note we investigate the existence of odd solutions of the congruence \begin{equation*} B_{n}(t)\equiv 1+rt\frac{t^{e(n)}-1}{t-1}\pmod{m}, \end{equation*} where mN2m\in\N_{\geq 2} and r{0,,m1}r\in\{0,\ldots,m-1\} are fixed and e(n)=\opdegBn(t)e(n)=\op{deg}B_{n}(t). We prove that for m=2m=2 and r{0,1}r\in\{0,1\} and for m=3m=3 and r=0r=0, there are infinitely many odd numbers nn satisfying the above congruence. We also present results of some numerical computations.

Keywords

Cite

@article{arxiv.1909.10844,
  title  = {Strong arithmetic property of certain Stern polynomials},
  author = {Maciej Ulas},
  journal= {arXiv preprint arXiv:1909.10844},
  year   = {2019}
}

Comments

revised version will appear in Publ. Math. Debrecen

R2 v1 2026-06-23T11:24:10.094Z