| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 42 |
| 5 | 582 |
| 6 | 21480 |
| 7 | 2142288 |
| 8 | 575016219 |
| 9 | 415939243032 |
| 10 | 816007449011040 |
| 11 | 4374406209970747314 |
| 12 | 64539836938720749739356 |
| 13 | 2637796735571225009053373136 |
| 14 | 300365896158980530053498490893399 |
[1,2,7,42,582,21480,2142288,575016219, 415939243032,816007449011040,4374406209970747314, 64539836938720749739356, 2637796735571225009053373136, 300365896158980530053498490893399] |