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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 9 |
| 4 | 93 |
| 5 | 1155 |
| 6 | 17025 |
| 7 | 292383 |
| 8 | 5752131 |
| 9 | 127790505 |
| 10 | 3167896005 |
| 11 | 86756071545 |
| 12 | 2602658092419 |
| 13 | 84917405260779 |
| 14 | 2994675198208785 |
| 15 | 113538315994418175 |
| 16 | 4606094297461892895 |
| 17 | 199122610252964803857 |
| 18 | 9139190793845641425261 |
| 19 | 443881600924216704982425 |
[0,0,1,9,93,1155,17025,292383,5752131,127790505, 3167896005,86756071545,2602658092419, 84917405260779,2994675198208785, 113538315994418175,4606094297461892895, 199122610252964803857,9139190793845641425261, 443881600924216704982425] |