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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 22 |
| 4 | 81 |
| 5 | 260 |
| 6 | 854 |
| 7 | 2738 |
| 8 | 8710 |
| 9 | 27550 |
| 10 | 86696 |
| 11 | 271726 |
| 12 | 848681 |
| 13 | 2642662 |
| 14 | 8207726 |
| 15 | 25434686 |
| 16 | 78663773 |
| 17 | 242865100 |
| 18 | 748650655 |
| 19 | 2304552576 |
| 20 | 7085109570 |
| 21 | 21757557324 |
| 22 | 66745430284 |
| 23 | 204559349854 |
| 24 | 626379255199 |
| 25 | 1916485240548 |
| 26 | 5859359429380 |
| 27 | 17901726707224 |
[1,2,8,22,81,260,854,2738,8710,27550,86696,271726, 848681,2642662,8207726,25434686,78663773, 242865100,748650655,2304552576,7085109570, 21757557324,66745430284,204559349854,626379255199, 1916485240548,5859359429380,17901726707224] |