C(27,11,2) = 9

Method of Construction: mills, ars combinatoria, 8 (1979) pg. 247

Lower Bound: Bounds for fixed number of blocks

  1  2  3  4  5  6  7  8  9 10 27
  1  2  3  4  5 11 12 13 14 15 27
  6  7  8  9 10 11 12 13 14 15 27
  1  2  3  4  5 16 17 18 19 20 21
  1  2  3  4  5 22 23 24 25 26 27
  6  7  8  9 10 16 17 18 22 23 24
  6  7  8  9 10 19 20 21 25 26 27
 11 12 13 14 15 16 17 18 25 26 27
 11 12 13 14 15 19 20 21 22 23 24