The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 1 |
| 8 | 7 |
| 9 | 63 |
| 10 | 458 |
| 11 | 3209 |
| 12 | 21160 |
| 13 | 135308 |
| 14 | 843204 |
| 15 | 5165292 |
[0,0,0,0,0,0,1,7,63,458,3209,21160,135308,843204, 5165292] |