| n | a(n) |
|---|---|
| 2 | 2 |
| 3 | 7 |
| 4 | 36 |
| 5 | 234 |
| 6 | 1096 |
| 7 | 6515 |
| 8 | 39238 |
| 9 | 253162 |
| 10 | 1671696 |
| 11 | 11247639 |
| 12 | 76975506 |
| 13 | 533525387 |
| 14 | 3728968546 |
| 15 | 26270971848 |
| 16 | 186444110128 |
[2,7,36,234,1096,6515,39238,253162,1671696, 11247639,76975506,533525387,3728968546, 26270971848,186444110128] |