Table 1: Triangle-free configurations for .


15 1 1 1 1 1 0
16 0 0 0 0 0 0
17 1 1 1 0 0 0
18 4 2 2 0 0 0
19 14 6 6 0 0 0
20 162 40 40 1 1 0
21 4,713 307 303 1 0 0
22 157,211 1,999 1,992 0 0 0

Note: is the number of configurations , is the number of self-dual configurations , is the number of self-polar configurations , is the number of point-transitive configurations , is the number of flag-transitive configurations , and is the number of blocking set free configurations .