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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 19 |
| 8 | 1784 |
| 9 | 55092 |
| 10 | 952640 |
| 11 | 11346508 |
| 12 | 103655440 |
| 13 | 774656344 |
| 14 | 4940080352 |
| 15 | 27682462431 |
[0,0,0,0,0,0,19,1784,55092,952640,11346508, 103655440,774656344,4940080352,27682462431] |