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| n | a(n) |
|---|---|
| 2 | 2 |
| 3 | 1 |
| 4 | 4 |
| 5 | 33 |
| 6 | 1621 |
| 7 | 3615901 |
| 8 | 18001725286324 |
| 9 | 447860502903416190825363096 |
| 10 | 277857758101409322438325757171462539621726973493284684 |
[2,1,4,33,1621,3615901,18001725286324, 447860502903416190825363096, 27785775810140932243832575717146253962172697349328\ 4684] |