| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 6 |
| 3 | 120 |
| 4 | 5040 |
| 5 | 5765760 |
| 6 | 19275223968000 |
| 7 | 13644281345408020027550269440000 |
| 8 | 4402827357584746886229433170489943024971625310770489684257669120000000000 |
[1,6,120,5040,5765760,19275223968000, 13644281345408020027550269440000, 44028273575847468862294331704899430249716253107704\ 89684257669120000000000] |