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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 6 |
| 6 | 0 |
| 7 | 96 |
| 8 | 272 |
| 9 | 1408 |
| 10 | 61622 |
| 11 | 33736 |
| 12 | 356606 |
| 13 | 86520774 |
| 14 | 192570133 |
| 15 | 1560696233 |
[1,0,0,0,6,0,96,272,1408,61622,33736,356606, 86520774,192570133,1560696233] |