lower bound = 12

C(18,6,2) = 12

Created by: LJCR

Method of Construction: Multiple of (9,3,2) covering

Lower Bound: Schonheim

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