\begin{center}
\footnotesize
\setlength{\mylength}{\baselineskip}
\begin{longtable}{rp{0ex}p{9cm}p{0ex}RL}
\caption{Laurent polynomials and selected mutations for bucket 7.}\\

\toprule \multicolumn{1}{c}{{Node}}&& \multicolumn{1}{c}{{Laurent polynomial}} && \multicolumn{2}{c}{{Mutations from Figure~\ref{fig:7a}}} \\ \midrule \endfirsthead

\multicolumn{6}{c}{{\tablename\ \thetable{} -- continued from previous page}} \\ \addlinespace[1.7ex] \midrule \multicolumn{1}{c}{{Node}}&& \multicolumn{1}{c}{{Laurent polynomial}} && \multicolumn{2}{c}{{Mutations from Figure~\ref{fig:7a}}} \\ \midrule \endhead

\midrule \multicolumn{6}{c}{{Continued on next page}} \endfoot

\bottomrule \endlastfoot

6 && $x+\frac{x}{yz}+y+z+\frac{1}{x}$ && $42 \colon {}$ & $\left(\frac{x^2yz+1}{x},\frac{x^2yz+1}{x^2y},\frac{x^2yz+1}{x^2z}\right)$ \bottomspacer \\ \addlinespace[1.1ex]
 \rowcolor[gray]{0.95}
42 && $xyz+x+y+z+\frac{1}{x}+\frac{1}{x^2z}+\frac{1}{x^2y}$ && $6 \colon {}$ & $\left(\frac{x^2+yz}{xyz},\frac{x^2z}{x^2+yz},\frac{x^2y}{x^2+yz}\right)$ \bottomspacer \\ \addlinespace[1.1ex]
 \end{longtable}
\end{center}
