| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 9 |
| 3 | 66 |
| 4 | 466 |
| 5 | 3267 |
| 6 | 22875 |
| 7 | 1120882 |
| 8 | 54923226 |
| 9 | 2691238083 |
| 10 | 131870666077 |
| 11 | 6461662637784 |
| 12 | 316621469251428 |
| 13 | 15514451993319985 |
| 14 | 760208147672679279 |
| 15 | 37250199235961284686 |
| 16 | 1825259762562102949630 |
| 17 | 89437728365543044531887 |
| 18 | 4382448689911609182062481 |
[1,9,66,466,3267,22875,1120882,54923226, 2691238083,131870666077,6461662637784, 316621469251428,15514451993319985, 760208147672679279,37250199235961284686, 1825259762562102949630,89437728365543044531887, 4382448689911609182062481] |