Rich dynamical behaviors from a digital reversal operation

Abstract

Repeatedly adding or subtracting the digital reversal to or from an integer, depending on which one is larger, can be treated as a dynamical system. On one hand, a three-digit version of this map running only two steps is the 1089 mathematical trick problem; on the other hand, this mapping can be compared to John Conway's reverse-add-then-sort (RATS) iteration, as well as the 3x+1 problem, also known as Collatz's map. We numerically run this map and find interesting dynamics, including limiting cycles with unusual periodicity and length-8 diverging trajectories.