15 ≤ C(31,19,4) ≤ 19

Created by: Kamal Fadlaoui

Method of Construction: Tabu Search

Lower Bound: Schonheim

  1  2  3  4  5  6  7 10 11 13 14 16 18 20 27 28 29 30 31
  1  2  3  4  6  7  8  9 10 12 15 17 19 20 21 22 24 26 31
  1  2  3  5  8 10 11 12 13 15 18 19 20 21 26 27 28 30 31
  1  2  3  5  9 10 11 13 17 18 20 22 23 24 25 27 28 30 31
  1  2  3  6  7  8  9 10 12 14 16 19 20 23 24 25 27 29 31
  1  2  4  5  7  8 12 14 15 16 17 18 19 20 21 25 26 28 29
  1  2  4  5  7  8 12 15 16 17 18 19 20 21 22 23 26 28 29
  1  2  4  5  8  9 11 12 13 16 17 18 19 20 24 27 28 29 30
  1  2  5  6  7  8 11 12 13 14 18 19 20 22 23 25 27 28 30
  1  2  5  6  7  9 11 13 14 15 17 18 20 21 24 26 27 28 30
  1  3  4  5 10 11 13 14 15 16 17 18 21 22 23 25 26 29 31
  1  4  5  6  9 14 15 16 17 18 21 22 23 24 25 26 27 29 30
  2  3  4 10 14 15 16 17 20 21 22 23 25 26 27 28 29 30 31
  2  4  6  9 11 13 14 15 16 17 20 21 22 23 24 25 26 28 29
  3  4  5  6  7  8  9 10 12 17 18 19 21 23 24 27 28 29 31
  3  4  6  7  8  9 10 11 12 13 14 16 17 19 21 24 25 30 31
  3  5  6  7  8  9 10 12 14 15 16 18 19 22 24 25 26 28 31
  3  6  7  8  9 10 11 12 13 15 19 22 23 24 26 27 29 30 31
  4  7  8 11 12 13 14 15 16 17 19 21 22 23 25 26 27 29 30