rank 3, subsets of the 13 lines {0,+-1}^3 with 3..9 lines: (n, status, exponents, supersolvable): count
   (3, 'free', (1, 1, 1), True) 246
   (3, 'nonessential', None, None) 40
   (4, 'free', (1, 1, 2), True) 364
   (4, 'nonessential', None, None) 9
   (4, 'notfree', None, False) 342
   (5, 'free', (1, 1, 3), True) 81
   (5, 'free', (1, 2, 2), True) 402
   (5, 'notfree', None, False) 804
   (6, 'free', (1, 2, 3), True) 306
   (6, 'notfree', None, False) 1410
   (7, 'free', (1, 3, 3), False) 26
   (7, 'free', (1, 3, 3), True) 264
   (7, 'notfree', None, False) 1426
   (8, 'free', (1, 3, 4), True) 96
   (8, 'notfree', None, False) 1191
   (9, 'free', (1, 3, 5), True) 8
   (9, 'free', (1, 4, 4), False) 72
   (9, 'notfree', None, False) 635
free and NOT supersolvable, by (n, exponents):
   (7, (1, 3, 3)) 26
   (9, (1, 4, 4)) 72
Lemma 1 test: pairs B < A of free arrangements: 72888, violations: 0
time 226.3s
