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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 8 |
| 3 | 71 |
| 4 | 680 |
| 5 | 6882 |
| 6 | 72528 |
| 7 | 788019 |
| 8 | 8766248 |
| 9 | 99362894 |
| 10 | 1143498224 |
| 11 | 13326176998 |
| 12 | 156950554384 |
| 13 | 1865210341828 |
| 14 | 22338852956064 |
| 15 | 269355965364459 |
| 16 | 3267146912972328 |
| 17 | 39837475762660374 |
| 18 | 488032452193307568 |
[1,1,8,71,680,6882,72528,788019,8766248,99362894, 1143498224,13326176998,156950554384,1865210341828, 22338852956064,269355965364459,3267146912972328, 39837475762660374,488032452193307568] |