13 ≤ C(23,12,3) ≤ 14
Method of Construction: simple construction: deleted element from c(v+1,k,t) covering
Lower Bound: Horsley-Singh, Theorem 6, s=1
1 2 3 4 9 10 11 12 17 18 19 20
1 2 5 6 9 10 13 14 17 18 21 22
1 2 7 8 9 10 12 15 16 17 18 23
1 3 5 7 9 11 13 15 17 19 21 23
1 3 6 8 9 11 12 14 16 17 19 22
1 3 4 5 8 9 12 13 16 17 20 21
1 4 6 7 9 12 14 15 17 20 22 23
2 3 4 5 8 10 11 13 16 18 19 21
2 3 6 7 10 11 14 15 18 19 22 23
2 4 5 7 10 12 13 15 18 20 21 23
2 4 6 8 10 12 14 15 16 18 20 22
3 4 5 6 11 12 13 14 19 20 21 22
3 4 6 7 8 11 12 15 16 19 20 23
5 6 7 8 9 13 14 15 16 21 22 23