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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 25 |
| 4 | 385 |
| 5 | 8661 |
| 6 | 255211 |
| 7 | 9280573 |
| 8 | 401106945 |
| 9 | 20075281705 |
| 10 | 1141518933811 |
| 11 | 72671265032961 |
| 12 | 5119905952974913 |
| 13 | 395447744211899965 |
| 14 | 33224120086567957275 |
| 15 | 3016468531370564888101 |
| 16 | 294296638636407727046401 |
| 17 | 30704676897459478866984273 |
| 18 | 3411268107193733242307499235 |
[1,1,3,25,385,8661,255211,9280573,401106945, 20075281705,1141518933811,72671265032961, 5119905952974913,395447744211899965, 33224120086567957275,3016468531370564888101, 294296638636407727046401, 30704676897459478866984273, 3411268107193733242307499235] |