b=1.600 reproduced start 38: depths [0.25 0.3  0.25], min T*(2) -0.010260
  pair parts [0.1517 1.0142 1.8754]  near [-3.934  -3.934  -2.8986 -2.8986 -1.8637 -1.8637 -0.7871 -0.7871  2.8126
  2.8126  3.8819  3.8819]
  quadrature T*(2) -0.01025988   closed form -0.01025988   diff 4.3e-14
  free depths: min T*(2) -0.016875, depths [0.275 0.326 0.271]
  same start, b=1.414: min T*(2) -0.079838
  same start, b=1.600: min T*(2) -0.010260
  same start, b=1.800: min T*(2) +0.105404
