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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 20 |
| 2 | 400 |
| 3 | 5362 |
| 4 | 71852 |
| 5 | 815677 |
| 6 | 9260610 |
| 7 | 94305342 |
| 8 | 958605819 |
| 9 | 8866424380 |
| 10 | 81766238574 |
| 11 | 692390232505 |
[1,20,400,5362,71852,815677,9260610,94305342, 958605819,8866424380,81766238574,692390232505] |