18 ≤ C(55,15,2) ≤ 19
Created by: LJCR
Method of Construction: Multiple of (11,3,2) covering
Lower Bound: Horsley, Theorem 1, r=4, d=2
1 2 6 12 13 17 23 24 28 34 35 39 45 46 50
1 3 11 12 14 22 23 25 33 34 36 44 45 47 55
1 4 9 12 15 20 23 26 31 34 37 42 45 48 53
1 5 8 12 16 19 23 27 30 34 38 41 45 49 52
1 7 10 12 18 21 23 29 32 34 40 43 45 51 54
2 3 8 13 14 19 24 25 30 35 36 41 46 47 52
2 4 10 13 15 21 24 26 32 35 37 43 46 48 54
2 5 11 13 16 22 24 27 33 35 38 44 46 49 55
2 7 9 13 18 20 24 29 31 35 40 42 46 51 53
3 4 11 14 15 22 25 26 33 36 37 44 47 48 55
3 5 7 14 16 18 25 27 29 36 38 40 47 49 51
3 6 10 14 17 21 25 28 32 36 39 43 47 50 54
3 9 11 14 20 22 25 31 33 36 42 44 47 53 55
4 5 6 15 16 17 26 27 28 37 38 39 48 49 50
4 7 8 15 18 19 26 29 30 37 40 41 48 51 52
5 9 10 16 20 21 27 31 32 38 42 43 49 53 54
6 7 11 17 18 22 28 29 33 39 40 44 50 51 55
6 8 9 17 19 20 28 30 31 39 41 42 50 52 53
8 10 11 19 21 22 30 32 33 41 43 44 52 54 55