The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 15 |
| 3 | 560 |
| 4 | 91390 |
| 5 | 61124064 |
| 6 | 163995687856 |
| 7 | 1756185841659392 |
| 8 | 75079359427627897200 |
| 9 | 12831653340946454374300160 |
| 10 | 8777916355714456994772455584000 |
| 11 | 24054320541767107204031746600673906688 |
[1,2,15,560,91390,61124064,163995687856, 1756185841659392,75079359427627897200, 12831653340946454374300160, 8777916355714456994772455584000, 24054320541767107204031746600673906688] |