The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 1 |
| 6 | 15 |
| 7 | 465 |
| 8 | 19355 |
| 9 | 1024380 |
| 10 | 66462606 |
| 11 | 5188453830 |
| 12 | 480413921130 |
| 13 | 52113376310985 |
| 14 | 6551246596501035 |
| 15 | 945313907253606891 |
| 16 | 155243722248524067795 |
| 17 | 28797220460586826422720 |
[1,0,0,0,0,1,15,465,19355,1024380,66462606, 5188453830,480413921130,52113376310985, 6551246596501035,945313907253606891, 155243722248524067795,28797220460586826422720] |