11 ≤ C(22,15,4) ≤ 12

Method of Construction: dynamic programming covering

Lower Bound: Schonheim

  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15
  1  2  3  4  5  6  7  8  9 10 11 12 13 16 17
  1  2  3  4  5  6  7  8  9 10 11 12 13 18 19
  1  2  3  4  5  6  7  8  9 10 11 12 13 20 21
  1  2  3  4  5  6  7  8  9 10 11 12 13 17 22
  1  2  3  4  5  6 14 15 16 17 18 19 20 21 22
  1  7  8  9 10 11 14 15 16 17 18 19 20 21 22
  2  3  7  8 12 13 14 15 16 17 18 19 20 21 22
  4  5  9 10 12 13 14 15 16 17 18 19 20 21 22
  2  3  6  9 10 11 14 15 16 17 18 19 20 21 22
  4  5  6  7  8 11 14 15 16 17 18 19 20 21 22
  1  2  6 11 12 13 14 15 16 17 18 19 20 21 22