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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 1 |
| 7 | 1 |
| 8 | 13 |
| 9 | 37 |
| 10 | 65 |
| 11 | 121 |
| 12 | 421 |
| 13 | 1309 |
| 14 | 3649 |
| 15 | 15177 |
| 16 | 81237 |
| 17 | 474405 |
| 18 | 2569641 |
| 19 | 13240801 |
| 20 | 84039101 |
| 21 | 586237485 |
[1,1,1,1,1,1,1,13,37,65,121,421,1309,3649,15177, 81237,474405,2569641,13240801,84039101,586237485] |