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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 48 |
| 3 | 6405442434150 |
| 4 | 213896868423550025518356115338261531036549426 |
[1,1,48,6405442434150, 213896868423550025518356115338261531036549426] |