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| n | a(n) |
|---|---|
| 0 | 2 |
| 1 | 1 |
| 2 | 5 |
| 3 | 25 |
| 4 | 161 |
| 5 | 1321 |
| 6 | 13025 |
| 7 | 149605 |
| 8 | 1963841 |
| 9 | 29004721 |
| 10 | 475975745 |
| 11 | 8591917885 |
| 12 | 169193833121 |
| 13 | 3609452038921 |
| 14 | 82924458549665 |
| 15 | 2041207822721365 |
| 16 | 53594538159184001 |
| 17 | 1495143168658285921 |
| 18 | 44164021453758342785 |
| 19 | 1377005070100813288045 |
| 20 | 45193800193226286112481 |
[2,1,5,25,161,1321,13025,149605,1963841,29004721, 475975745,8591917885,169193833121,3609452038921, 82924458549665,2041207822721365,53594538159184001, 1495143168658285921,44164021453758342785, 1377005070100813288045,45193800193226286112481] |