\begin {tabular}{cc}dof&error1\\\pgfutilensuremath {9}&\pgfutilensuremath {0.25}\\\pgfutilensuremath {25}&\pgfutilensuremath {6.25\cdot 10^{-2}}\\\pgfutilensuremath {81}&\pgfutilensuremath {1.56\cdot 10^{-2}}\\\pgfutilensuremath {289}&\pgfutilensuremath {3.91\cdot 10^{-3}}\\\pgfutilensuremath {1{,}089}&\pgfutilensuremath {9.77\cdot 10^{-4}}\\\pgfutilensuremath {4{,}225}&\pgfutilensuremath {2.44\cdot 10^{-4}}\\\pgfutilensuremath {16{,}641}&\pgfutilensuremath {6.1\cdot 10^{-5}}\\\pgfutilensuremath {66{,}049}&\pgfutilensuremath {1.53\cdot 10^{-5}}\\\pgfutilensuremath {2.63\cdot 10^{5}}&\pgfutilensuremath {3.81\cdot 10^{-6}}\\\pgfutilensuremath {1.05\cdot 10^{6}}&\pgfutilensuremath {9.54\cdot 10^{-7}}\\\end {tabular}
