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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 3 |
| 3 | 15 |
| 4 | 84 |
| 5 | 497 |
| 6 | 2862 |
| 7 | 15420 |
| 8 | 86570 |
| 9 | 484976 |
| 10 | 2751326 |
| 11 | 15597305 |
| 12 | 89022483 |
| 13 | 508390703 |
| 14 | 2915183250 |
| 15 | 16739260404 |
| 16 | 96360825455 |
| 17 | 555513635334 |
| 18 | 3208071753051 |
| 19 | 18550893260858 |
| 20 | 107413402302763 |
| 21 | 622649366897782 |
| 22 | 3613180083184007 |
[3,3,15,84,497,2862,15420,86570,484976,2751326, 15597305,89022483,508390703,2915183250, 16739260404,96360825455,555513635334, 3208071753051,18550893260858,107413402302763, 622649366897782,3613180083184007] |