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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 384 |
| 4 | 173946175488 |
| 5 | 1592481597212922365761871004823571903636713118111555911680 |
[1,4,384,173946175488, 15924815972129223657618710048235719036367131181115\ 55911680] |