15 ≤ C(55,16,2) ≤ 16

Created by: Jan de Heer and Steve Muir

Method of Construction: Private tools

Lower Bound: Horsley, Theorem 11, r=4, d=6

  1  2 10 13 16 18 20 23 27 31 37 43 46 47 51 54
  1  3  5  6  7  9 11 12 16 18 20 24 26 39 48 54
  1  4 14 16 18 20 21 25 29 33 38 40 41 42 44 54
  1  8 16 18 19 20 22 28 32 36 45 49 50 52 54 55
  1  9 10 15 17 21 25 30 33 34 35 36 44 45 53 55
  2  3  4  5 24 28 29 36 40 41 42 43 45 50 51 55
  2  6  7  9 11 12 14 19 21 25 32 33 43 44 49 51
  2  8 15 17 22 26 30 34 35 38 39 43 48 51 52 53
  3  5  8 10 14 21 22 24 25 31 33 37 44 46 47 52
  3  5 13 15 17 19 23 24 27 30 32 34 35 38 49 53
  4  6  7  8  9 11 12 13 22 23 27 29 40 41 42 52
  4  7 12 14 15 16 17 28 29 30 34 35 37 41 50 53
  4 10 19 26 29 31 32 37 39 40 41 42 46 47 48 49
  6  7  9 10 11 12 28 31 36 37 38 45 46 47 50 55
  6 11 15 17 18 20 30 31 34 35 40 42 46 47 53 54
 13 14 21 23 25 26 27 28 33 36 39 44 45 48 50 55