\begin{center}
\footnotesize
\setlength{\mylength}{\baselineskip}
\begin{longtable}{rp{0ex}p{9cm}p{0ex}RL}
\caption{Laurent polynomials and selected mutations for bucket 45.}\\

\toprule \multicolumn{1}{c}{{Node}}&& \multicolumn{1}{c}{{Laurent polynomial}} && \multicolumn{2}{c}{{Mutations from Figure~\ref{fig:45a}}} \\ \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:45a}}} \\ \midrule \endhead

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

\bottomrule \endlastfoot

18 && $x+y+z+\frac{1}{y}+\frac{2}{x}+\frac{1}{x^2z}$ && $31 \colon {}$ & $\left(\frac{y+z}{yz},x,\frac{z^2}{y+z}\right)$ \bottomspacer \\ \addlinespace[1.1ex]
 \rowcolor[gray]{0.95}
31 && $x+y+z+\frac{1}{z}+\frac{1}{y}+\frac{1}{x}$ && $18 \colon {}$ & $\left(y,\frac{xz+1}{x^2z},\frac{xz+1}{x}\right)$ \spacer \\* \rowcolor[gray]{0.95}
 &&  && $156 \colon {}$ & $\left(\frac{x^2yz+xy+1}{x},\frac{x^3yz}{x^2yz+xy+1},\frac{x^2yz+xy+1}{x^2y}\right)$ \bottomspacer \\ \addlinespace[1.1ex]
 122 && $x+y+z+\frac{3}{x}+\frac{z}{xy}+\frac{1}{x^2z}+\frac{2}{x^2y}+\frac{1}{x^3yz}$ && $156 \colon {}$ & $\left(x,\frac{x^2yz+1}{x^2y},\frac{1}{x^3yz}\right)$ \bottomspacer \\ \addlinespace[1.1ex]
 \rowcolor[gray]{0.95}
156 && $xyz+x+y+z+\frac{3}{x}+\frac{1}{x^2z}+\frac{1}{x^2y}+\frac{1}{x^3yz}$ && $31 \colon {}$ & $\left(\frac{xyz+x+z}{xz},\frac{x^2}{xyz+x+z},\frac{xyz^2}{xyz+x+z}\right)$ \spacer \\* \rowcolor[gray]{0.95}
 &&  && $122 \colon {}$ & $\left(x,\frac{xz+1}{x^3yz},\frac{y}{xz+1}\right)$ \bottomspacer \\ \addlinespace[1.1ex]
 \end{longtable}
\end{center}
