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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 12 |
| 3 | 51 |
| 4 | 225 |
| 5 | 1018 |
| 6 | 4682 |
| 7 | 21792 |
| 8 | 102357 |
| 9 | 484186 |
| 10 | 2303423 |
| 11 | 11009216 |
| 12 | 52822832 |
| 13 | 254278092 |
| 14 | 1227475473 |
| 15 | 5939756449 |
| 16 | 28803320496 |
| 17 | 139934359516 |
| 18 | 680961029062 |
| 19 | 3318631373717 |
| 20 | 16194557374944 |
| 21 | 79121838008508 |
| 22 | 386983559520381 |
| 23 | 1894591409599364 |
| 24 | 9283866303696064 |
| 25 | 45530276736993243 |
| 26 | 223460832994759113 |
[1,3,12,51,225,1018,4682,21792,102357,484186, 2303423,11009216,52822832,254278092,1227475473, 5939756449,28803320496,139934359516,680961029062, 3318631373717,16194557374944,79121838008508, 386983559520381,1894591409599364,9283866303696064, 45530276736993243,223460832994759113] |