We prove that the reversible elementary second order cellular automaton rule 115 is periodic when started on finite initial configurations. We also study some families of finite configurations that have interesting period functions.

翻译：我们证明了可逆基本二阶元胞自动机规则115在有限初始构型下具有周期性。我们还研究了若干具有有趣周期函数的有限构型族。