lower bound = 28

C(28,6,2) = 28

Method of Construction: cyclic covering found by search program

Lower Bound: Schonheim

  1  2  5 16 21 23
  2  3  6 17 22 24
  3  4  7 18 23 25
  4  5  8 19 24 26
  5  6  9 20 25 27
  6  7 10 21 26 28
  1  7  8 11 22 27
  2  8  9 12 23 28
  1  3  9 10 13 24
  2  4 10 11 14 25
  3  5 11 12 15 26
  4  6 12 13 16 27
  5  7 13 14 17 28
  1  6  8 14 15 18
  2  7  9 15 16 19
  3  8 10 16 17 20
  4  9 11 17 18 21
  5 10 12 18 19 22
  6 11 13 19 20 23
  7 12 14 20 21 24
  8 13 15 21 22 25
  9 14 16 22 23 26
 10 15 17 23 24 27
 11 16 18 24 25 28
  1 12 17 19 25 26
  2 13 18 20 26 27
  3 14 19 21 27 28
  1  4 15 20 22 28