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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 20 |
| 3 | 1109 |
| 4 | 149777 |
| 5 | 40505320 |
| 6 | 19324787629 |
| 7 | 14885613436177 |
| 8 | 17346023517866756 |
| 9 | 29095672934852234945 |
| 10 | 67554301929824585326841 |
| 11 | 210353969049597164741983000 |
| 12 | 855886755812900060235077981449 |
| 13 | 4452236180954942685194928540509281 |
[1,1,20,1109,149777,40505320,19324787629, 14885613436177,17346023517866756, 29095672934852234945,67554301929824585326841, 210353969049597164741983000, 855886755812900060235077981449, 4452236180954942685194928540509281] |