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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 1228 |
| 4 | 14089656148992 |
| 5 | 50346839734076286938886836265405905350164480 |
[1,1,2,1228,14089656148992, 50346839734076286938886836265405905350164480] |