The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 5 |
| 7 | 13 |
| 8 | 45 |
| 9 | 141 |
| 10 | 593 |
| 11 | 2479 |
| 12 | 13149 |
| 13 | 73679 |
| 14 | 588757 |
| 15 | 5000629 |
| 16 | 56709831 |
| 17 | 657094563 |
[1,1,1,1,1,5,13,45,141,593,2479,13149,73679, 588757,5000629,56709831,657094563] |