Finite projective plane
7 point
- (1, 2, 3), (1, 4, 5), (1, 6, 7), (2, 4, 6), (2, 5, 7), (3, 4, 7), (3, 5, 6).
13 point
- (1, 2, 3, 4), (1, 5, 6, 7), (1, 8, 9, 10), (1, 11, 12, 13), (2, 5, 8, 11), (2, 6, 9, 12), (2, 7, 10, 13), (3, 5, 10, 12), (3, 6, 8, 13), (3, 7, 9, 11), (4, 5, 9, 13), (4, 6, 10, 11), (4, 7, 8, 12).