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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 9 |
| 3 | 43 |
| 4 | 242 |
| 5 | 1437 |
| 6 | 9058 |
| 7 | 59062 |
| 8 | 396207 |
| 9 | 2713848 |
| 10 | 18906784 |
| 11 | 133534659 |
| 12 | 953964640 |
| 13 | 6881027743 |
| 14 | 50044650836 |
[1,2,9,43,242,1437,9058,59062,396207,2713848, 18906784,133534659,953964640,6881027743, 50044650836] |