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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 17 |
| 4 | 57 |
| 5 | 781 |
| 6 | 24351 |
| 7 | 931801 |
| 8 | 62200649 |
| 9 | 8963823755 |
| 10 | 2146203654665 |
| 11 | 870522837091137 |
| 12 | 672438522925983773 |
[1,1,17,57,781,24351,931801,62200649,8963823755, 2146203654665,870522837091137,672438522925983773] |