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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 3 |
| 3 | 120 |
| 4 | 48456 |
| 5 | 263380794 |
| 6 | 24387010797162 |
| 7 | 46238305131413696652 |
[0,3,120,48456,263380794,24387010797162, 46238305131413696652] |