lower bound = 12

C(9,3,2) = 12

Method of Construction: affine geometry covering

Lower Bound: Schonheim

  1  4  7
  2  5  8
  3  6  9
  1  6  8
  2  4  9
  3  5  7
  1  5  9
  2  6  7
  3  4  8
  1  2  3
  4  5  6
  7  8  9