Frattini length
From Groupprops
This article defines an arithmetic function on a restricted class of groups, namely: finite groups
Definition
Symbol-free definition
Given a finite group, we define the Frattini length as follows: the length of the Frattini series. The Frattini series is the descending series corresponding to the Frattini subgroup, that is, it is obtained by iterating the subgroup-defining function namely the Frattini subgroup.