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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 30 |
| 4 | 390 |
| 5 | 6270 |
| 6 | 36894 |
| 7 | 528990 |
| 8 | 6373290 |
| 9 | 32222190 |
| 10 | 3180844590 |
| 11 | 2248482390 |
[1,2,30,390,6270,36894,528990,6373290,32222190, 3180844590,2248482390] |