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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | 2 |
| 4 | 9 |
| 5 | 435 |
| 6 | 20375 |
| 7 | 1624164 |
| 8 | 170338575 |
| 9 | 23301045360 |
| 10 | 4006433553814 |
| 11 | 845857620264286 |
| 12 | 215056002391454266 |
[1,0,2,9,435,20375,1624164,170338575,23301045360, 4006433553814,845857620264286,215056002391454266] |