31 ≤ C(18,7,3) ≤ 33

Created by: Roy Gourgi

Method of Construction: Extraction/remainder

Lower Bound: Schonheim

  1  2  3  4  7 15 17
  1  2  3  5  6  9 13
  1  2  3  8 10 11 12
  1  2  3 13 14 16 18
  1  3  4  8 11 15 16
  1  4  5  7 10 15 18
  1  4  5  9 10 16 17
  1  4  5  9 12 15 18
  1  4  6 10 13 14 15
  1  5  7  8  9 11 14
  1  5  8 12 14 16 17
  1  6  7 12 13 16 17
  1  6  8 11 13 17 18
  2  4  5  7 13 16 18
  2  4  6  7  9 11 12
  2  4  7  8  9 10 14
  2  5  8 10 13 15 17
  2  5  9 11 12 13 14
  2  6  8  9 10 16 18
  2  6  8  9 14 15 17
  2 11 12 15 16 17 18
  3  4  5  6  8  9 18
  3  4  6 10 11 13 16
  3  4  9 10 12 14 16
  3  5  6  7 10 12 17
  3  5  6 11 14 15 16
  3  7  8 13 14 16 17
  3  7  9 11 14 17 18
  3  9 10 12 13 15 18
  4  5 10 11 14 17 18
  4  6  8  9 12 13 17
  6  7  8 12 14 15 18
  7  9 10 11 13 15 16