\begin{center}
\footnotesize
\setlength{\mylength}{\baselineskip}
\begin{longtable}{rp{0ex}p{9cm}p{0ex}RL}
\caption{Laurent polynomials and selected mutations for bucket 46.}\\

\toprule \multicolumn{1}{c}{{Node}}&& \multicolumn{1}{c}{{Laurent polynomial}} && \multicolumn{2}{c}{{Mutations from Figure~\ref{fig:46a}}} \\ \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:46a}}} \\ \midrule \endhead

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

\bottomrule \endlastfoot

43 && $x+y+z+\frac{1}{y}+\frac{y}{xz}+\frac{2}{x}+\frac{1}{x^2z}$ && $221 \colon {}$ & $\left(\frac{x^2yz+(xz+1)^2}{x^2z},\frac{x^2yz+(xz+1)^2}{x^3yz},\frac{x^3z^2}{x^2yz+(xz+1)^2}\right)$ \bottomspacer \\ \addlinespace[1.1ex]
 \rowcolor[gray]{0.95}
68 && $x+y+z+\frac{1}{z}+\frac{1}{y}+\frac{1}{x}+\frac{1}{xyz}$ && $246 \colon {}$ & $\left(\frac{x^2z}{xy+xz+1},\frac{x^2y}{xy+xz+1},\frac{xy+xz+1}{x}\right)$ \bottomspacer \\ \addlinespace[1.1ex]
 221 && $x+y+z+\frac{3}{x}+\frac{z}{xy}+\frac{2}{x^2z}+\frac{3}{x^2y}+\frac{3}{x^3yz}+\frac{1}{x^4yz^2}$ && $43 \colon {}$ & $\left(\frac{x^2z+y(xz+1)^2}{x^2yz},\frac{x^3z}{x^2z+y(xz+1)^2},\frac{x^3yz^2}{x^2z+y(xz+1)^2}\right)$ \spacer \\* 
 &&  && $246 \colon {}$ & $\left(x,\frac{z(xy+1)}{xy},y\right)$ \bottomspacer \\ \addlinespace[1.1ex]
 \rowcolor[gray]{0.95}
246 && $x+y+z+\frac{y}{xz}+\frac{3}{x}+\frac{z}{xy}+\frac{2}{x^2z}+\frac{2}{x^2y}+\frac{1}{x^3yz}$ && $68 \colon {}$ & $\left(\frac{xz+yz+1}{z},\frac{yz^2}{xz+yz+1},\frac{xz^2}{xz+yz+1}\right)$ \spacer \\* \rowcolor[gray]{0.95}
 &&  && $221 \colon {}$ & $\left(x,z,\frac{xyz}{xz+1}\right)$ \bottomspacer \\ \addlinespace[1.1ex]
 \end{longtable}
\end{center}
