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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 32 |
| 4 | 504 |
| 5 | 15704 |
| 6 | 967040 |
| 7 | 117706400 |
| 8 | 28318463392 |
| 9 | 13466466727872 |
| 10 | 12657620455508224 |
| 11 | 23516077513008447744 |
| 12 | 86355918572493456505728 |
| 13 | 626806864356196966410513920 |
| 14 | 8992693476394949632573847880832 |
[1,4,32,504,15704,967040,117706400,28318463392, 13466466727872,12657620455508224, 23516077513008447744,86355918572493456505728, 626806864356196966410513920, 8992693476394949632573847880832] |