11 ≤ C(20,11,3) ≤ 12

Created by: Jan de Heer

Lower Bound: Schonheim

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