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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 3 |
| 7 | 23 |
| 8 | 43 |
| 9 | 81 |
| 10 | 319 |
| 11 | 1397 |
| 12 | 6447 |
| 13 | 41775 |
| 14 | 230237 |
| 15 | 1798489 |
| 16 | 13587111 |
| 17 | 143546329 |
| 18 | 1450499749 |
| 19 | 20575847369 |
| 20 | 276390467445 |
| 21 | 5233548027451 |
| 22 | 93375391444657 |
[1,1,1,1,1,3,23,43,81,319,1397,6447,41775,230237, 1798489,13587111,143546329,1450499749,20575847369, 276390467445,5233548027451,93375391444657] |