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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 5 |
| 4 | 41 |
| 5 | 469 |
| 6 | 6889 |
| 7 | 123605 |
| 8 | 2620169 |
| 9 | 64074901 |
| 10 | 1775623081 |
| 11 | 54989743445 |
| 12 | 1882140936521 |
| 13 | 70552399533589 |
| 14 | 2874543652787689 |
| 15 | 126484802362553045 |
| 16 | 5977683917752887689 |
| 17 | 301983995802099667861 |
| 18 | 16239818347465293071401 |
| 19 | 926248570498763547197525 |
| 20 | 55847464116157184894240201 |
[1,1,5,41,469,6889,123605,2620169,64074901, 1775623081,54989743445,1882140936521, 70552399533589,2874543652787689, 126484802362553045,5977683917752887689, 301983995802099667861,16239818347465293071401, 926248570498763547197525, 55847464116157184894240201] |