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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 4 |
| 3 | 32 |
| 4 | 278 |
| 5 | 2250 |
| 6 | 18839 |
| 7 | 162662 |
| 8 | 1433999 |
| 9 | 12811208 |
| 10 | 115798814 |
[0,4,32,278,2250,18839,162662,1433999,12811208, 115798814] |