C(20,11,2) = 6

Method of Construction: lex covering

Lower Bound: Bounds for fixed number of blocks

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