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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 9 |
| 3 | 54 |
| 4 | 482 |
| 5 | 4239 |
| 6 | 55561 |
| 7 | 785554 |
| 8 | 14133055 |
| 9 | 285547760 |
| 10 | 6666380256 |
| 11 | 172748192767 |
| 12 | 4974178683908 |
| 13 | 156462697434990 |
| 14 | 5354832107694444 |
| 15 | 197710292330150160 |
| 16 | 7839473395324929677 |
| 17 | 332071887435037103895 |
| 18 | 14968498613432649146050 |
| 19 | 715294449027151380463781 |
[1,1,9,54,482,4239,55561,785554,14133055, 285547760,6666380256,172748192767,4974178683908, 156462697434990,5354832107694444, 197710292330150160,7839473395324929677, 332071887435037103895,14968498613432649146050, 715294449027151380463781] |