m=120: tried 1074, 22s, 2log_3(m)=8.72; top (excess, t, k, d-log2b, log2b/m):
  0.41 12 77 8.84 0.51
  0.37 13 51 7.94 0.48
  0.10 11 50 7.59 0.55
  -0.09 16 37 7.89 0.38
  -0.32 13 56 6.85 0.49
  -0.38 9 53 6.90 0.63
m=240: tried 4483, 348s, 2log_3(m)=9.98; top (excess, t, k, d-log2b, log2b/m):
  1.76 11 145 9.77 0.77
  0.76 11 146 8.18 0.77
  0.72 17 111 7.88 0.68
  -0.24 11 147 6.60 0.78
  -0.28 17 112 6.30 0.68
  -0.72 16 133 6.44 0.70
