C(18,8,2) = 7

Method of Construction: simple construction: induced on c(19,9,3) covering

Lower Bound: Schonheim

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