n=8: 1925 reachable points with |B|<=60, 596 direction classes
distinct patterns: class | (preclosed length / shortest , reduced factor) ... | unreduced factor tuples -> number of direction classes
  class even | 1.00000:x1  2.41421:x1 | {(4, 4): 136} | n among reduced factors: False
  class odd  | 1.00000:x2  1.41421:x1 | {(2, 1): 460} | n among reduced factors: False
longest closed trajectory met: 312 bounces
direction classes with a reduced factor equal to n: 0 of 596
Theorem 7(a) on these direction classes: every (unreduced) factor divides n/2: True (1192 bands)
exact decisions: 49777, time 2.7s
