The Maximum Length for Ducci Sequences on $\mathbb{}Z_m^n$ when $n$ is Even

Abstract

Let $D: \mathbb{Z}_m^n \to \mathbb{Z}_m^n$ be defined so \[D(x_1, x_2, ..., x_n)=(x_1+x_2 \; \text{mod} \; m, x_2+x_3 \; \text{mod} \; m, ..., x_n+x_1 \; \text{mod} \; m).\] $D$ is known as the Ducci function and for $\mathbf{u} \in \mathbb{Z}_m^n$, $\{D^α(\mathbf{u})\}_{α=0}^{\infty}$ is the Ducci sequence of $\mathbf{u}$. Every Ducci sequence enters a cycle because $\mathbb{Z}_m^n$ is finite. In this paper, we aim to establish an upper bound for how long it will take for a Ducci sequence in $\mathbb{Z}_m^n$ to enter its cycle when $n$ is even.

Figures (1)

• Figure 1: Transition Graph for $\mathbb{Z}_2^6$

Theorems & Definitions (13)

• Definition 1
• Theorem 2
• Theorem 3
• proof : Proof of Theorem \ref{['n_even_m_odd_preds']}
• Lemma 4
• proof
• Lemma 5
• proof
• Lemma 6
• proof