\begin{table}%t3
%\centering
\par
\caption{\label{sjs21}Coefficients $M_{j,k}$ of the Jupiter-Saturn secular system at the
  end of the simulation illustrated in Fig.~\ref{c21}.}
\begin{tabular}{ccc}
 \hline\hline
$_j\setminus^k$\quad\hbox{} & 5& 6  
\\\hline 
5 & 0.00272& 0.00275\\ 
6 &  0.0378& 0.0854\\  
 \hline 
\end{tabular}
\end{table}