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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 17 |
| 3 | 119 |
| 4 | 866 |
| 5 | 6328 |
| 6 | 46211 |
| 7 | 337274 |
| 8 | 2460918 |
| 9 | 17953576 |
| 10 | 130970758 |
| 11 | 955393448 |
| 12 | 6969190236 |
| 13 | 50836821440 |
| 14 | 370827923908 |
| 15 | 2704988609708 |
| 16 | 19731401249156 |
| 17 | 143929610463264 |
| 18 | 1049886222652688 |
| 19 | 7658333144969252 |
| 20 | 55863255070913284 |
[1,17,119,866,6328,46211,337274,2460918,17953576, 130970758,955393448,6969190236,50836821440, 370827923908,2704988609708,19731401249156, 143929610463264,1049886222652688,7658333144969252, 55863255070913284] |