2 \item Lower bound\footnote{T. Feder and C. Subi.
3 \newblock Nearly tight bounds on the number of hamiltonian circuits of the
4 hypercube and generalizations.
5 \newblock {\em Inf. Process. Lett.}, 109(5):267--272, February 2009.} of number of Gray codes in $\Bool^n$: $\left(\frac{n*\log2}{e \log \log n}*(1 - o(1))\right)^{2^n}$ (more than $10^{13}$ when n is 6).
7 \item Restriction to balanced codes: the number of edges that modify
8 the bit $i$ in $\Gamma(f)$ have to be close to each other
12 \begin{exampleblock}{Study of previous code}
14 \begin{minipage}{0.70\textwidth}
17 \item $L^*=000,100,101,001,011,111,110,010$
18 \item Its transition sequence: $S=3,1,3,2,3,1,3,2$
19 %\item Its transition count function: $\textit{TC}_3(1)= \textit{TC}_3(2)=2$ and $\textit{TC}_3(3)=4$.
23 \begin{minipage}{0.29\textwidth}
25 \hspace{-2.8cm}\includegraphics[scale=0.5]{iter_f0e}