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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 14 |
| 4 | 32 |
| 5 | 82 |
| 6 | 196 |
| 7 | 464 |
| 8 | 1142 |
| 9 | 2746 |
| 10 | 6576 |
| 11 | 15976 |
| 12 | 38484 |
| 13 | 92544 |
| 14 | 223790 |
| 15 | 539402 |
| 16 | 1299184 |
| 17 | 3136178 |
| 18 | 7560760 |
| 19 | 18222032 |
| 20 | 43956888 |
| 21 | 105980632 |
| 22 | 255487040 |
| 23 | 616137680 |
| 24 | 1485562228 |
| 25 | 3581617536 |
| 26 | 8636505982 |
| 27 | 20823634954 |
| 28 | 50206996848 |
[1,2,6,14,32,82,196,464,1142,2746,6576,15976, 38484,92544,223790,539402,1299184,3136178,7560760, 18222032,43956888,105980632,255487040,616137680, 1485562228,3581617536,8636505982,20823634954, 50206996848] |