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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 1 |
| 6 | 3 |
| 7 | 5 |
| 8 | 21 |
| 9 | 49 |
| 10 | 187 |
| 11 | 409 |
| 12 | 2325 |
| 13 | 6489 |
| 14 | 55121 |
| 15 | 197983 |
| 16 | 2161765 |
| 17 | 11768363 |
| 18 | 152495079 |
| 19 | 1086067425 |
| 20 | 18675930957 |
| 21 | 164918184657 |
| 22 | 3873609933855 |
[1,1,1,3,1,3,5,21,49,187,409,2325,6489,55121, 197983,2161765,11768363,152495079,1086067425, 18675930957,164918184657,3873609933855] |