Index divisibility in the orbit of 0 for integral polynomials

Abstract

Let $f(x) \in \bbz[x]$ and consider the index divisibility set $D = \{n \in \bbn : n \mid f^n(0)\}$. We present a number of properties of $D$ in the case that $(f^n(0){)}_{n=1}^{\infty }$ is a rigid divisibility sequence, generalizing a number of results of Chen, Stange, and the first author. We then study the polynomial $x^d + x^e + c \in \bbz[x]$, where $d>e\ge 2$ and determine all cases where this map has a finite index divisibility set.

References in corpus (3)

• The terms in Lucas sequences divisible by their indices
• Index Divisibility in Dynamical Sequences and Cyclic Orbits Modulo $p$
• The density of the terms in an elliptic divisibility sequence having a fixed G.C.D. with their index