C(13,12,2) = 3

Method of Construction: lex covering

Lower Bound: Schonheim

  1  2  3  4  5  6  7  8  9 10 11 12
  1  2  3  4  5  6  7  8  9 10 11 13
  1  2  3  4  5  6  7  8  9 10 12 13