Avec les paquetage pst-tree.
\newcommand{\N}{\Tcircle[fillstyle=solid,fillcolor=black]{ }}
\newcommand{\B}{\Tcircle[fillstyle=solid,fillcolor=white]{ }}
\pstree[treemode=R]{\Tr{}}
{
\pstree{\B^{3/5}}
{
\pstree{\B^{2/4}}
{
\pstree{\B^{1/3}}
{
\N_{2/2}
}
\N_{2/3}
}
\N_{2/4}
}
\N_{2/5}}