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| n | a(n) |
|---|---|
| 1 | 9 |
| 2 | 63 |
| 3 | 513 |
| 4 | 3423 |
| 5 | 18589 |
| 6 | 73035 |
| 7 | 225479 |
| 8 | 617215 |
| 9 | 1622001 |
| 10 | 4300263 |
| 11 | 12128763 |
| 12 | 37076783 |
| 13 | 122411649 |
| 14 | 427600575 |
| 15 | 1550703157 |
| 16 | 5759666431 |
| 17 | 21738733961 |
| 18 | 82999762711 |
| 19 | 319722139579 |
| 20 | 1240393764207 |
| 21 | 4840363237201 |
| 22 | 18979321319087 |
| 23 | 74713018378209 |
| 24 | 295061102101311 |
[9,63,513,3423,18589,73035,225479,617215,1622001, 4300263,12128763,37076783,122411649,427600575, 1550703157,5759666431,21738733961,82999762711, 319722139579,1240393764207,4840363237201, 18979321319087,74713018378209,295061102101311] |