2: 0.512282851198 3: 0.631652057640 4: 0.712795473791 7: 0.751745228811 19: 0.773986575243 27: 0.781176288426 28: 0.800193270075 2 3 4 7 19 27 28 Fit of radii by a power law r = a0*n^a1: a0 = 0.72513 a1 = -0.45827