Published online by Cambridge University Press: 22 November 2019
A Ducci sequence is a sequence of integer $n$-tuples obtained by iterating the map
$$\begin{eqnarray}D:(a_{1},a_{2},\ldots ,a_{n})\mapsto (|a_{1}-a_{2}|,|a_{2}-a_{3}|,\ldots ,|a_{n}-a_{1}|).\end{eqnarray}$$
$P(n)$ the maximal period of such sequences for given odd
$n$. We prove a lower bound for
$P(n)$ by counting certain partitions. We then estimate the size of these partitions via the multiplicative order of two modulo
$n$.
The second author was supported in part by the Australian Research Council Grant DP180100201.