| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 12 |
| 4 | 60 |
| 5 | 180 |
| 6 | 900 |
| 7 | 1800 |
| 8 | 3600 |
| 9 | 18000 |
| 10 | 54000 |
| 11 | 162000 |
| 12 | 486000 |
| 13 | 2430000 |
| 14 | 4860000 |
| 15 | 9720000 |
| 16 | 29160000 |
| 17 | 58320000 |
| 18 | 116640000 |
| 19 | 583200000 |
| 20 | 1749600000 |
| 21 | 5248800000 |
| 22 | 10497600000 |
| 23 | 31492800000 |
| 24 | 62985600000 |
| 25 | 188956800000 |
[1,2,6,12,60,180,900,1800,3600,18000,54000,162000, 486000,2430000,4860000,9720000,29160000,58320000, 116640000,583200000,1749600000,5248800000, 10497600000,31492800000,62985600000,188956800000] |