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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 22 |
| 4 | 219 |
| 5 | 2530 |
| 6 | 31830 |
| 7 | 422652 |
| 8 | 5820099 |
| 9 | 82226522 |
| 10 | 1183598754 |
| 11 | 17277560996 |
| 12 | 254957527134 |
| 13 | 3795103401236 |
| 14 | 56900877433356 |
| 15 | 858486641574392 |
| 16 | 13025190180880851 |
| 17 | 198640087778490698 |
| 18 | 3043793354165966442 |
| 19 | 46845889623804326292 |
| 20 | 723896233987491887466 |
| 21 | 11227150555314722435580 |
[1,3,22,219,2530,31830,422652,5820099,82226522, 1183598754,17277560996,254957527134,3795103401236, 56900877433356,858486641574392,13025190180880851, 198640087778490698,3043793354165966442, 46845889623804326292,723896233987491887466, 11227150555314722435580] |