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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 9 |
| 3 | 39 |
| 4 | 156 |
| 5 | 626 |
| 6 | 2505 |
| 7 | 10023 |
| 8 | 40092 |
| 9 | 160370 |
| 10 | 641481 |
| 11 | 2565927 |
| 12 | 10263708 |
| 13 | 41054834 |
| 14 | 164219337 |
| 15 | 656877351 |
| 16 | 2627509404 |
| 17 | 10510037618 |
| 18 | 42040150473 |
| 19 | 168160601895 |
| 20 | 672642407580 |
| 21 | 2690569630322 |
| 22 | 10762278521289 |
| 23 | 43049114085159 |
[2,9,39,156,626,2505,10023,40092,160370,641481, 2565927,10263708,41054834,164219337,656877351, 2627509404,10510037618,42040150473,168160601895, 672642407580,2690569630322,10762278521289, 43049114085159] |