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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 22 |
| 3 | 282 |
| 4 | 2778 |
| 5 | 23305 |
| 6 | 175194 |
| 7 | 1215740 |
| 8 | 7939156 |
| 9 | 49422491 |
| 10 | 295993366 |
| 11 | 1717056604 |
| 12 | 9697408184 |
| 13 | 53533130211 |
| 14 | 289769871988 |
| 15 | 1541876281342 |
| 16 | 8081886977224 |
| 17 | 41801262603145 |
| 18 | 213650877117460 |
| 19 | 1080407596025856 |
[1,22,282,2778,23305,175194,1215740,7939156, 49422491,295993366,1717056604,9697408184, 53533130211,289769871988,1541876281342, 8081886977224,41801262603145,213650877117460, 1080407596025856] |