\documentclass[12pt]{article} \usepackage{amsmath,mathrsfs,bbm} \usepackage{amssymb} \textwidth=4.825in \overfullrule=0pt \thispagestyle{empty} \begin{document} \noindent % % {\bf Song-Tao Guo, Jin-Xin Zhou and Yan-Quan Feng} % % \medskip \noindent % % {\bf Pentavalent Symmetric Graphs of Order $12p$} % % \vskip 5mm \noindent % % % % A graph is said to be {\em symmetric} if its automorphism group acts transitively on its arcs. In this paper, a complete classification of connected pentavalent symmetric graphs of order $12p$ is given for each prime $p$. As a result, a connected pentavalent symmetric graph of order $12p$ exists if and only if $p=2$, $3$, $5$ or $11$, and up to isomorphism, there are only nine such graphs: one for each $p=2$, $3$ and $5$, and six for $p=11$. \end{document} .