The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 4 | 1 |
| 5 | 7 |
| 6 | 25 |
| 7 | 70 |
| 8 | 430 |
| 9 | 2529 |
| 10 | 13389 |
| 11 | 123723 |
| 12 | 1442773 |
| 13 | 16315566 |
| 14 | 272990681 |
| 15 | 5489382645 |
[1,7,25,70,430,2529,13389,123723,1442773,16315566, 272990681,5489382645] |