C(23,11,2) = 7

Method of Construction: lex covering

Lower Bound: Schonheim

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