C(24,9,2) = 11

Method of Construction: lex covering

Lower Bound: Handbook of Combinatorial Designs section on coverings

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