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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 5 |
| 3 | 1700 |
| 4 | 601120000 |
| 5 | 3496121614336000000 |
| 6 | 5335507266769461885009920000000000 |
| 7 | 34161019296423817239835748940949012820787200000000000000 |
[1,5,1700,601120000,3496121614336000000, 5335507266769461885009920000000000, 34161019296423817239835748940949012820787200000000\ 000000] |