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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 2 |
| 3 | 11 |
| 4 | 105 |
| 5 | 878 |
| 6 | 8321 |
| 7 | 79418 |
| 8 | 780436 |
| 9 | 7766817 |
| 10 | 78293570 |
| 11 | 796665063 |
| 12 | 8171931384 |
[0,2,11,105,878,8321,79418,780436,7766817, 78293570,796665063,8171931384] |