\begin{tikzpicture}

\def\n {5}
\def\radius {2cm}

\foreach \i in {1,...,\n}
{
  \node[draw, circle] (v\i) at ({-360/\n * (\i+2)}:\radius) {$\i$};
}

  \draw[->] (v3) -- (v1);
  \draw[->] (v4) -- (v3);
  \draw[->] (v5) -- (v4);
\end{tikzpicture}