Unicursal polygram

I worked out on unicursal pattern on polygram and found that the sequence does not exist for distinct patterns excluded differential on orientations and reflections.
The sequence showed as following:
n          unicursal pattern
3                     1
4                     2
5                     4
6                   12
7                   36
8                 162
9                 648      Forecast from OEIS A007694 
10             2592      Forecast from OEIS A007694
11           11664      Forecast from OEIS A007694
12           46656      Forecast from OEIS A007694    
. . . . . . . . . . . . .

What are number of unicursal pattern for n > 8 ?