C(26,4,2) = 59
Method of Construction: simple construction: combined (25,4,2) and (25,3,1)-coverings
Lower Bound: Schonheim
3 6 16 25
5 12 16 17
8 21 23 25
7 11 16 23
1 10 11 21
3 17 20 21
3 11 13 14
1 7 20 24
14 16 18 20
12 14 19 23
10 13 22 23
4 6 17 23
3 7 10 18
1 3 12 22
5 13 18 21
4 9 10 15
8 9 12 18
7 13 17 19
4 14 22 24
15 16 21 22
5 7 9 22
5 15 20 23
15 17 18 24
4 11 18 25
2 6 7 8
6 9 14 21
2 9 13 16
3 8 15 19
8 10 16 24
6 10 12 20
2 19 21 24
3 9 23 24
1 4 16 19
6 18 19 22
2 11 12 15
8 11 17 22
12 13 24 25
5 6 11 24
2 20 22 25
1 9 17 25
5 10 19 25
9 11 19 20
2 3 4 5
4 7 12 21
4 8 13 20
7 14 15 25
1 2 18 23
1 6 13 15
2 10 14 17
1 5 8 14
1 2 3 26
4 5 6 26
7 8 9 26
10 11 12 26
13 14 15 26
16 17 18 26
19 20 21 26
22 23 24 26
9 11 25 26