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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 16 |
| 4 | 1296 |
| 5 | 20736 |
| 6 | 12960000 |
| 7 | 4320000 |
| 8 | 10372320000 |
| 9 | 165957120000 |
| 10 | 40327580160000 |
| 11 | 40327580160000 |
| 12 | 590436101122560000 |
| 13 | 590436101122560000 |
| 14 | 16863445484161436160000 |
| 15 | 2409063640594490880000 |
| 16 | 2409063640594490880000 |
[1,1,16,1296,20736,12960000,4320000,10372320000, 165957120000,40327580160000,40327580160000, 590436101122560000,590436101122560000, 16863445484161436160000,2409063640594490880000, 2409063640594490880000] |