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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 10 |
| 5 | 44 |
| 6 | 249 |
| 7 | 1513 |
| 8 | 9992 |
| 9 | 68305 |
| 10 | 480748 |
| 11 | 3450793 |
| 12 | 25186583 |
[1,1,1,3,10,44,249,1513,9992,68305,480748,3450793, 25186583] |