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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 8 |
| 3 | 31 |
| 4 | 297 |
| 5 | 5613 |
| 6 | 218980 |
| 7 | 11901719 |
| 8 | 1341217380 |
| 9 | 375045359077 |
| 10 | 204902495620748 |
| 11 | 208094348433251495 |
[1,8,31,297,5613,218980,11901719,1341217380, 375045359077,204902495620748,208094348433251495] |