C(26,6,2) = 24

Method of Construction: found by a hill-climbing program

Lower Bound: Handbook of Combinatorial Designs section on coverings

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