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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 18 |
| 3 | 504 |
| 4 | 19152 |
| 5 | 919296 |
| 6 | 53319168 |
| 7 | 3625703424 |
| 8 | 282804867072 |
| 9 | 24886828302336 |
| 10 | 2438909173628928 |
| 11 | 263402190751924224 |
| 12 | 31081458508727058432 |
| 13 | 3978426689117063479296 |
| 14 | 549022883098154760142848 |
| 15 | 81255386698526904501141504 |
| 16 | 12838351098367250911180357632 |
[1,18,504,19152,919296,53319168,3625703424, 282804867072,24886828302336,2438909173628928, 263402190751924224,31081458508727058432, 3978426689117063479296,549022883098154760142848, 81255386698526904501141504, 12838351098367250911180357632] |