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| n | a(n) |
|---|---|
| 1 | 18 |
| 2 | 324 |
| 3 | 5813 |
| 4 | 103983 |
| 5 | 1866632 |
| 6 | 33457393 |
| 7 | 599230909 |
| 8 | 10742524446 |
| 9 | 192455268439 |
[18,324,5813,103983,1866632,33457393,599230909, 10742524446,192455268439] |