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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 5 |
| 3 | 17 |
| 4 | 86 |
| 5 | 698 |
| 6 | 9551 |
| 7 | 217041 |
| 8 | 7494325 |
| 9 | 373961481 |
| 10 | 24759614016 |
| 11 | 2084532681440 |
| 12 | 216682611479515 |
| 13 | 27184833539127138 |
[2,5,17,86,698,9551,217041,7494325,373961481, 24759614016,2084532681440,216682611479515, 27184833539127138] |