13 ≤ C(23,15,4) ≤ 15

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 22 23
  1  2  3  4  5 14 15 16 17 18 19 20 21 22 23
  1  6  7  8  9 14 15 16 17 18 19 20 21 22 23
  1 10 11 12 13 14 15 16 17 18 19 20 21 22 23
  2  3  6  7 10 14 15 16 17 18 19 20 21 22 23
  2  3  8  9 11 14 15 16 17 18 19 20 21 22 23
  4  5  6  7 11 14 15 16 17 18 19 20 21 22 23
  4  5  8  9 10 14 15 16 17 18 19 20 21 22 23
  2  3  4 12 13 14 15 16 17 18 19 20 21 22 23
  5  6  7 12 13 14 15 16 17 18 19 20 21 22 23
  1  8  9 12 13 14 15 16 17 18 19 20 21 22 23