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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 1 |
| 3 | 48 |
| 4 | 322 |
| 5 | 1517 |
| 6 | 3476 |
| 7 | 45998 |
| 8 | 405818 |
| 9 | 591216 |
| 10 | 43220379 |
| 11 | 172187609 |
[4,1,48,322,1517,3476,45998,405818,591216, 43220379,172187609] |