C(28,12,2) = 7

Created by: LJCR

Method of Construction: Multiple of (14,6,2) covering

Lower Bound: Schonheim

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