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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 5 |
| 5 | 29 |
| 6 | 139 |
| 7 | 901 |
| 8 | 5485 |
| 9 | 74291 |
| 10 | 1056181 |
| 11 | 24810777 |
| 12 | 651071773 |
| 13 | 25748617719 |
| 14 | 1169149922235 |
| 15 | 81072042123257 |
| 16 | 6590052771959131 |
[1,1,1,5,29,139,901,5485,74291,1056181,24810777, 651071773,25748617719,1169149922235, 81072042123257,6590052771959131] |