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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 9 |
| 3 | 167 |
| 4 | 4780 |
| 5 | 186004 |
| 6 | 9173780 |
| 7 | 548563140 |
| 8 | 38573633016 |
| 9 | 3119384230176 |
| 10 | 285237426927552 |
| 11 | 29102185296785160 |
| 12 | 3277703460197645232 |
| 13 | 403931173342682581296 |
| 14 | 54066960915411480743520 |
| 15 | 7811249803193620134996864 |
| 16 | 1211525560869437165319590400 |
[1,1,9,167,4780,186004,9173780,548563140, 38573633016,3119384230176,285237426927552, 29102185296785160,3277703460197645232, 403931173342682581296,54066960915411480743520, 7811249803193620134996864, 1211525560869437165319590400] |