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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 0 |
| 6 | 3 |
| 7 | 1 |
| 8 | 13 |
| 9 | 10 |
| 10 | 66 |
| 11 | 112 |
| 12 | 723 |
| 13 | 2283 |
| 14 | 12616 |
| 15 | 62163 |
| 16 | 372147 |
| 17 | 2268021 |
| 18 | 15209245 |
| 19 | 107306496 |
[0,0,0,1,0,3,1,13,10,66,112,723,2283,12616,62163, 372147,2268021,15209245,107306496] |