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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 8 |
| 4 | 38 |
| 5 | 102 |
| 6 | 192 |
| 7 | 786 |
| 8 | 2214 |
| 9 | 4598 |
| 10 | 17906 |
| 11 | 51306 |
| 12 | 112928 |
| 13 | 425882 |
| 14 | 1232454 |
| 15 | 2818458 |
| 16 | 10393254 |
| 17 | 30269862 |
| 18 | 71152482 |
| 19 | 257993706 |
| 20 | 754758738 |
| 21 | 1811628498 |
| 22 | 6482271054 |
| 23 | 19026456246 |
| 24 | 46431160992 |
| 25 | 164353672602 |
| 26 | 483626452302 |
| 27 | 1196266880906 |
| 28 | 4196480707814 |
[1,2,6,8,38,102,192,786,2214,4598,17906,51306, 112928,425882,1232454,2818458,10393254,30269862, 71152482,257993706,754758738,1811628498, 6482271054,19026456246,46431160992,164353672602, 483626452302,1196266880906,4196480707814] |