lower bound = 11

C(11,4,2) = 11

Method of Construction: cyclic covering found by a search program

Lower Bound: Schonheim

  2  3  4  7
  3  4  5  8
  4  5  6  9
  5  6  7 10
  6  7  8 11
  1  7  8  9
  2  8  9 10
  3  9 10 11
  1  4 10 11
  1  2  5 11
  1  2  3  6