lower bound = 19

C(26,7,2) = 19

Created by: Jan de Heer

Lower Bound: Schonheim

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