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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 12 |
| 4 | 447 |
| 5 | 47412 |
| 6 | 13756977 |
| 7 | 10906862650 |
| 8 | 23635238362194 |
| 9 | 140000241129382544 |
[0,1,12,447,47412,13756977,10906862650, 23635238362194,140000241129382544] |