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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 31 |
| 4 | 133 |
| 5 | 586 |
| 6 | 2650 |
| 7 | 12189 |
| 8 | 56736 |
| 9 | 266741 |
| 10 | 1262802 |
| 11 | 6014765 |
| 12 | 28782488 |
| 13 | 138282827 |
| 14 | 666545461 |
| 15 | 3221898963 |
| 16 | 15611199126 |
| 17 | 75798945036 |
| 18 | 368705744764 |
| 19 | 1796352068703 |
| 20 | 8764345076617 |
| 21 | 42815139898679 |
| 22 | 209396441863843 |
| 23 | 1025148827454705 |
| 24 | 5023528239350538 |
| 25 | 24637644686786875 |
| 26 | 120927928674405187 |
[1,2,8,31,133,586,2650,12189,56736,266741,1262802, 6014765,28782488,138282827,666545461,3221898963, 15611199126,75798945036,368705744764, 1796352068703,8764345076617,42815139898679, 209396441863843,1025148827454705,5023528239350538, 24637644686786875,120927928674405187] |