\begin{figure}[H]
  \begin{center}
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    \gasset{Nw=5,Nh=5,Nmr=2.5,curvedepth=0}
    \thinlines
    \node[Nmarks=i,iangle=180](A0)(0,0){$0$}
    \node[Nmarks=f,fangle=0](A1)(20,0){$1$}
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  \end{center}
  \caption{Puissances de $2$.}
\end{figure}