\begin{center}
\footnotesize
\setlength{\mylength}{\baselineskip}
\begin{longtable}{rp{0ex}p{9cm}p{0ex}RL}
\caption{Laurent polynomials and selected mutations for bucket 4.}\\

\toprule \multicolumn{1}{c}{{Node}}&& \multicolumn{1}{c}{{Laurent polynomial}} && \multicolumn{2}{c}{{Mutations from Figure~\ref{fig:4a}}} \\ \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:4a}}} \\ \midrule \endhead

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

\bottomrule \endlastfoot

14 && $x+y+z+\frac{z}{xy}+\frac{2}{xy}+\frac{1}{xyz}$ && $23 \colon {}$ & $\left(x,\frac{xyz+1}{xz},xyz\right)$ \bottomspacer \\ \addlinespace[1.1ex]
 \rowcolor[gray]{0.95}
23 && $xyz+x+y+z+\frac{1}{xz}+\frac{1}{xy}$ && $14 \colon {}$ & $\left(x,\frac{yz}{z+1},\frac{z+1}{xy}\right)$ \bottomspacer \\ \addlinespace[1.1ex]
 \end{longtable}
\end{center}
