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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 9 |
| 2 | 72 |
| 3 | 576 |
| 4 | 4608 |
| 5 | 36864 |
| 6 | 294912 |
| 7 | 2359296 |
| 8 | 18874368 |
| 9 | 150994908 |
| 10 | 1207958976 |
| 11 | 9663669540 |
| 12 | 77309338176 |
| 13 | 618474560256 |
| 14 | 4947795320832 |
| 15 | 39582353276928 |
| 16 | 316658751897600 |
| 17 | 2533269420638208 |
| 18 | 20266150608766188 |
| 19 | 162129166819422768 |
[1,9,72,576,4608,36864,294912,2359296,18874368, 150994908,1207958976,9663669540,77309338176, 618474560256,4947795320832,39582353276928, 316658751897600,2533269420638208, 20266150608766188,162129166819422768] |