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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 159 |
| 3 | 9054 |
| 4 | 467899 |
| 5 | 22309009 |
| 6 | 999810316 |
| 7 | 42764566838 |
| 8 | 1764109373799 |
| 9 | 70707661248442 |
| 10 | 2768685594929370 |
| 11 | 106349114580207849 |
| 12 | 4020025709583200998 |
| 13 | 149916029504065737481 |
| 14 | 5526692782368686983855 |
| 15 | 201739654709622213459404 |
[4,159,9054,467899,22309009,999810316,42764566838, 1764109373799,70707661248442,2768685594929370, 106349114580207849,4020025709583200998, 149916029504065737481,5526692782368686983855, 201739654709622213459404] |