The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 2 |
| 5 | 10 |
| 6 | 53 |
| 7 | 376 |
| 8 | 3379 |
| 9 | 37408 |
| 10 | 485680 |
| 11 | 7150241 |
| 12 | 116726073 |
| 13 | 2085446355 |
[0,0,1,2,10,53,376,3379,37408,485680,7150241, 116726073,2085446355] |