# energies
n	calculated	exact
  1	   -0.497	   -0.500
  2	   -0.125	   -0.125
  3	   -0.056	   -0.056
  4	   -0.030	   -0.031
  5	   -0.007	   -0.020
  6	    0.025	   -0.014
  7	    0.066	   -0.010
  8	    0.115	   -0.008
  9	    0.172	   -0.006