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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 0 |
| 9 | 18 |
| 10 | 40 |
| 11 | 66 |
| 12 | 0 |
| 13 | 0 |
| 14 | 0 |
| 15 | 0 |
| 16 | 0 |
| 17 | 0 |
| 18 | 400686 |
| 19 | 1738012 |
| 20 | 8495580 |
| 21 | 0 |
| 22 | 0 |
| 23 | 0 |
| 24 | 0 |
| 25 | 0 |
| 26 | 0 |
[1,1,0,0,0,0,0,0,0,18,40,66,0,0,0,0,0,0,400686, 1738012,8495580,0,0,0,0,0,0] |