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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 16 |
| 5 | 45 |
| 6 | 129 |
| 7 | 367 |
| 8 | 1081 |
| 9 | 3098 |
| 10 | 9291 |
| 11 | 26788 |
| 12 | 81341 |
| 13 | 235729 |
| 14 | 722479 |
| 15 | 2102856 |
| 16 | 6492146 |
| 17 | 18965527 |
| 18 | 58898531 |
| 19 | 172600126 |
| 20 | 538640825 |
| 21 | 1582733185 |
| 22 | 4959648919 |
| 23 | 14607576158 |
| 24 | 45935431662 |
| 25 | 135571479679 |
| 26 | 427621459608 |
| 27 | 1264356405112 |
| 28 | 3998682343629 |
| 29 | 11842126315245 |
| 30 | 37540318975749 |
[1,2,6,16,45,129,367,1081,3098,9291,26788,81341, 235729,722479,2102856,6492146,18965527,58898531, 172600126,538640825,1582733185,4959648919, 14607576158,45935431662,135571479679,427621459608, 1264356405112,3998682343629,11842126315245, 37540318975749] |