General Dynamics and Generation Mapping for Collatz-type Sequences

TL;DR

This paper introduces a novel framework using General Dynamics and Generation Mapping to analyze Collatz-type sequences, revealing properties of governors and cycles, and providing evidence against the existence of divergent integers in the 3Z+1 sequence.

Contribution

It develops a new mapping approach to understand the structure of Collatz-type sequences, identifying the behavior of governors and cycles, and proving the absence of auxiliary cycles and divergent integers.

Findings

All odd integers with repeating sequences have specific trivial governors.

No auxiliary cycles exist in the 3Z+1 sequence.

Smallest odd integers in auxiliary cycles are less than 32.

Abstract

Let an odd integer \(\mathcal{X}\) be expressed as $\left\{\sum\limits_{M > m}b_M2^M\right\}+2^m-1,$ where $b_M\in\{0,1\}$ and $2^m-1$ is referred to as the Governor. In Collatz-type functions, a high index Governor is eventually reduced to $2^1-1$. For the $3\mathcal{Z}+1$ sequence, the Governor occurring in the Trivial cycle is $2^1-1$, while for the $5\mathcal{Z}+1$ sequence, the Trivial Governors are $2^2-1$ and $2^1-1$. Therefore, in these specific sequences, the Collatz function reduces the Governor $2^m - 1$ to the Trivial Governor $2^{\mathcal{T}} - 1$. Once this Trivial Governor is reached, it can evolve to a higher index Governor through interactions with other terms. This feature allows $\mathcal{X}$ to reappear in a Collatz-type sequence, since $2^m - 1 = 2^{m - 1} + \cdots + 2^{\mathcal{T} + 1} + 2^{\mathcal{T}}+(2^{\mathcal{T}}-1).$ Thus, if $\mathcal{X}$ reappears, at least one odd ancestor of $\left\{\sum\limits_{M > m}b_M2^M\right\}+2^{m-1}+\cdots+2^{\mathcal{T}+1}+2^{\mathcal{T}}+(2^{\mathcal{T}}-1)$ must have the Governor $2^m-1$. Ancestor mapping shows that all odd ancestors of $\mathcal{X}$ have the Trivial Governor for the respective Collatz sequence. This implies that odd integers that repeat in the $3\mathcal{Z} + 1$ sequence have the Governor $2^1 - 1$, while those forming a repeating cycle in the $5\mathcal{Z} + 1$ sequence have either $2^2 - 1$ or $2^1 - 1$ as the Governor. Successor mapping for the $3\mathcal{Z} + 1$ sequence further indicates that there are no auxiliary cycles, as the Trivial Governor is always transformed into a different index Governor. Similarly, successor mapping for the $5\mathcal{Z} + 1$ sequence reveals that the smallest odd integers forming an auxiliary cycle are smaller than $2^5$. Finally, attempts to identify integers that diverge for the $3\mathcal{Z} + 1$ sequence suggest that no such integers exist.