n=7: 1931 reachable points with |B|<=60, 476 direction classes
distinct patterns: class | (preclosed length / shortest , reduced factor) ... | unreduced factor tuples -> number of direction classes
  class -    | 1.00000:x1  1.80194:x1  2.24698:x1 | {(7, 7, 7): 419, (1, 1, 1): 57} | n among reduced factors: False
longest closed trajectory met: 1050 bounces
direction classes with a reduced factor equal to n: 0 of 476
Theorem 7(b) on these direction classes: classes 476 ; with exactly m=3 bands of distinct preclosed length: 476 ; preclosed lengths proportional to sin(2j pi/n): 476 ; factors = n/gcd(n, alpha*j) for some alpha: 476 ; gcd(alpha, n) -> number of classes: {1: 419, 7: 57}
exact decisions: 188446, time 10.5s
