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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 15 |
| 3 | 159 |
| 4 | 2191 |
| 5 | 30295 |
| 6 | 421471 |
| 7 | 5797959 |
| 8 | 79367143 |
| 9 | 1079774311 |
| 10 | 14630901175 |
| 11 | 197520668295 |
| 12 | 2659138662775 |
| 13 | 35714778101863 |
| 14 | 478783751931415 |
| 15 | 6408527754114375 |
| 16 | 85670414104756855 |
| 17 | 1144076540594898727 |
[2,15,159,2191,30295,421471,5797959,79367143, 1079774311,14630901175,197520668295,2659138662775, 35714778101863,478783751931415,6408527754114375, 85670414104756855,1144076540594898727] |