C(26,5,2) = 37
Method of Construction: simple construction: combined (25,5,2) and (25,4,1)-coverings
Lower Bound: Schonheim
1 7 13 19 25
2 8 14 20 21
3 9 15 16 22
4 10 11 17 23
5 6 12 18 24
1 10 14 18 22
2 6 15 19 23
3 7 11 20 24
4 8 12 16 25
5 9 13 17 21
1 6 11 16 21
2 7 12 17 22
3 8 13 18 23
4 9 14 19 24
5 10 15 20 25
1 2 3 4 5
6 7 8 9 10
11 12 13 14 15
16 17 18 19 20
21 22 23 24 25
1 9 12 20 23
2 10 13 16 24
3 6 14 17 25
4 7 15 18 21
5 8 11 19 22
1 8 15 17 24
2 9 11 18 25
3 10 12 19 21
4 6 13 20 22
5 7 14 16 23
1 2 3 4 26
5 6 7 8 26
9 10 11 12 26
13 14 15 16 26
17 18 19 20 26
21 22 23 24 26
14 17 24 25 26