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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 68 |
| 6 | 46 |
| 7 | 221 |
| 8 | 757 |
| 9 | 5518 |
| 10 | 65106 |
| 11 | 1293698 |
| 12 | 3997147 |
| 13 | 4009564363 |
[1,2,4,68,46,221,757,5518,65106,1293698,3997147, 4009564363] |