C(25,6,2) = 23

Method of Construction: simulated annealing covering

Lower Bound: Schonheim

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