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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 5 |
| 3 | 13 |
| 4 | 3767 |
| 5 | 19913 |
| 6 | 726109 |
| 7 | 4827859 |
| 8 | 59069473 |
| 9 | 179993463679 |
| 10 | 2280987436223 |
[2,5,13,3767,19913,726109,4827859,59069473, 179993463679,2280987436223] |