| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 56 |
| 4 | 13833 |
| 5 | 6699824 |
| 6 | 5691917785 |
| 7 | 7785547001784 |
| 8 | 16086070907249329 |
| 9 | 47799861987366600992 |
| 10 | 196500286135805946117201 |
| 11 | 1082973554682091552092493880 |
| 12 | 7797122311868240909226166565881 |
[1,0,1,56,13833,6699824,5691917785,7785547001784, 16086070907249329,47799861987366600992, 196500286135805946117201, 1082973554682091552092493880, 7797122311868240909226166565881] |