17 ≤ C(54,15,2) ≤ 18

Created by: LJCR

Method of Construction: Multiple of (18,5,2) covering

Lower Bound: Horsley, Theorem 11, r=4, d=3

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