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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 9 |
| 4 | 99 |
| 5 | 1301 |
| 6 | 20581 |
| 7 | 376891 |
| 8 | 7914216 |
| 9 | 186905206 |
| 10 | 4915451602 |
| 11 | 142368695176 |
| 12 | 4506118905870 |
| 13 | 154720069309364 |
| 14 | 5729167232515112 |
| 15 | 227585086051159866 |
| 16 | 9654819212943764500 |
| 17 | 435659280972794395356 |
| 18 | 20836049921760968809231 |
| 19 | 1052864549462731148832219 |
[0,1,9,99,1301,20581,376891,7914216,186905206, 4915451602,142368695176,4506118905870, 154720069309364,5729167232515112, 227585086051159866,9654819212943764500, 435659280972794395356,20836049921760968809231, 1052864549462731148832219] |