lower bound = 15

C(15,7,3) = 15

Method of Construction: cyclic covering found by search program

Lower Bound: Schonheim

  1  2  3  5  6  9 11
  2  3  4  6  7 10 12
  3  4  5  7  8 11 13
  4  5  6  8  9 12 14
  5  6  7  9 10 13 15
  1  6  7  8 10 11 14
  2  7  8  9 11 12 15
  1  3  8  9 10 12 13
  2  4  9 10 11 13 14
  3  5 10 11 12 14 15
  1  4  6 11 12 13 15
  1  2  5  7 12 13 14
  2  3  6  8 13 14 15
  1  3  4  7  9 14 15
  1  2  4  5  8 10 15