13 ≤ C(19,10,3) ≤ 14

Method of Construction: covering found by a hill-climbing program

Lower Bound: Horsley-Singh, Theorem 6, s=1

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