n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 6 |
3 | 27 |
4 | 124 |
5 | 645 |
6 | 3906 |
7 | 27391 |
8 | 219192 |
9 | 1972809 |
10 | 19728190 |
11 | 217010211 |
12 | 2604122676 |
13 | 33853594957 |
14 | 473950329594 |
15 | 7109254944135 |
16 | 113748079106416 |
17 | 1933717344809361 |
18 | 34806912206568822 |
19 | 661331331924807979 |
[0,1,6,27,124,645,3906,27391,219192,1972809, 19728190,217010211,2604122676,33853594957, 473950329594,7109254944135,113748079106416, 1933717344809361,34806912206568822, 661331331924807979] |