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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 23 |
| 5 | 210 |
| 6 | 1996 |
| 7 | 20661 |
| 8 | 205366 |
| 9 | 2048662 |
| 10 | 20502004 |
| 11 | 204951472 |
[0,0,1,23,210,1996,20661,205366,2048662,20502004, 204951472] |