C(27,9,2) = 12

Created by: LJCR

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

Lower Bound: Schonheim

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