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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 301 |
| 3 | 1510 |
| 4 | 90901 |
| 5 | 456015 |
| 6 | 27451801 |
| 7 | 137715020 |
| 8 | 8290353001 |
| 9 | 41589480025 |
| 10 | 2503659154501 |
| 11 | 12559885252530 |
| 12 | 756096774306301 |
| 13 | 3793043756784035 |
| 14 | 228338722181348401 |
| 15 | 1145486654663526040 |
| 16 | 68957538001992910801 |
| 17 | 345933176664628080045 |
[1,5,301,1510,90901,456015,27451801,137715020, 8290353001,41589480025,2503659154501, 12559885252530,756096774306301,3793043756784035, 228338722181348401,1145486654663526040, 68957538001992910801,345933176664628080045] |