| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 96 |
| 5 | 480 |
| 6 | 207360 |
| 7 | 1451520 |
| 8 | 2972712960 |
| 9 | 722369249280 |
| 10 | 5778953994240000 |
| 11 | 63568493936640000 |
| 12 | 9111096278347394580480000 |
| 13 | 118444251618516129546240000 |
| 14 | 10400352846118664303196241920000 |
[1,2,6,96,480,207360,1451520,2972712960, 722369249280,5778953994240000,63568493936640000, 9111096278347394580480000, 118444251618516129546240000, 10400352846118664303196241920000] |