I'm loking for this relation:
\begin{equation}
\Gamma^c_{ab}=-\Omega_{ab}\,^c+\Omega_b\,^c\,_a-\Omega^c\,_{ab} \end{equation}
where $\Omega$ is:
\begin{equation}
\Omega_{ab}\,^c=e^\mu\,_ae^\nu\,_b\partial_{[\mu}e_{\nu]}\,^c
\end{equation}
But i have an extra term and i don't understand where is...