14 ≤ C(20,10,3) ≤ 15

Method of Construction: lex covering

Lower Bound: Schonheim

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