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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 12 |
| 5 | 57 |
| 6 | 366 |
| 7 | 2324 |
| 8 | 16044 |
| 9 | 113593 |
| 10 | 830667 |
| 11 | 6204230 |
| 12 | 47241109 |
| 13 | 365363530 |
[1,1,2,12,57,366,2324,16044,113593,830667,6204230, 47241109,365363530] |