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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 9 |
| 3 | 23 |
| 4 | 51 |
| 5 | 175 |
| 6 | 513 |
| 7 | 1397 |
| 8 | 4133 |
| 9 | 12075 |
| 10 | 34521 |
| 11 | 100047 |
| 12 | 290287 |
| 13 | 838039 |
| 14 | 2423841 |
| 15 | 7016381 |
| 16 | 20290449 |
| 17 | 58686583 |
| 18 | 169784637 |
| 19 | 491117363 |
| 20 | 1420584719 |
| 21 | 4109370831 |
| 22 | 11887034385 |
| 23 | 34384871493 |
| 24 | 99464136973 |
| 25 | 287716480627 |
| 26 | 832264983105 |
[1,9,23,51,175,513,1397,4133,12075,34521,100047, 290287,838039,2423841,7016381,20290449,58686583, 169784637,491117363,1420584719,4109370831, 11887034385,34384871493,99464136973,287716480627, 832264983105] |