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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 9 |
| 3 | 35 |
| 4 | 135 |
| 5 | 535 |
| 6 | 2103 |
| 7 | 8255 |
| 8 | 32895 |
| 9 | 131711 |
| 10 | 525695 |
| 11 | 2098687 |
| 12 | 8395263 |
| 13 | 33561599 |
| 14 | 134233087 |
| 15 | 536887295 |
| 16 | 2147516415 |
| 17 | 8590229503 |
| 18 | 34360360959 |
| 19 | 137439608831 |
| 20 | 549758566399 |
| 21 | 2199026139135 |
| 22 | 8796099051519 |
| 23 | 35184378380287 |
| 24 | 140737540784127 |
| 25 | 562950007947263 |
[2,9,35,135,535,2103,8255,32895,131711,525695, 2098687,8395263,33561599,134233087,536887295, 2147516415,8590229503,34360360959,137439608831, 549758566399,2199026139135,8796099051519, 35184378380287,140737540784127,562950007947263] |