Author:
Hajati Farnoosh,Iranmanesh Ali,Tehranian Abolfazl
Abstract
Let $G$ be a finite group and $\omega(G)$ be the set of element orders of $G$. Let $k\in\omega(G)$ and $m_k$ be the number of elements of order $k$ in $G$. Let $ nse(G)=\{m_k|k\in \omega(G)\}$. The aim of this paper is to prove that, if $G$ is a finite group such that nse($G$)=nse($U_4(2)$), then $G\cong U_4(2)$.