| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 28 |
| 3 | 1638 |
| 4 | 30240 |
| 5 | 2178540 |
| 6 | 2457000 |
| 7 | 32997888 |
| 8 | 142990848 |
| 9 | 1307124000 |
| 10 | 71271827200 |
| 11 | 547929930240 |
| 12 | 2198278051200 |
| 13 | 2567400675840 |
| 14 | 54409216942080 |
[1,28,1638,30240,2178540,2457000,32997888, 142990848,1307124000,71271827200,547929930240, 2198278051200,2567400675840,54409216942080] |