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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 5 |
| 5 | 18 |
| 6 | 51 |
| 7 | 131 |
| 8 | 309 |
| 9 | 694 |
| 10 | 1494 |
| 11 | 3117 |
| 12 | 6320 |
| 13 | 12514 |
| 14 | 24234 |
| 15 | 46016 |
| 16 | 85790 |
| 17 | 157301 |
| 18 | 283982 |
| 19 | 505432 |
| 20 | 887692 |
| 21 | 1539969 |
| 22 | 2640920 |
| 23 | 4480467 |
| 24 | 7524824 |
| 25 | 12518126 |
| 26 | 20638663 |
| 27 | 33739438 |
| 28 | 54713975 |
| 29 | 88052156 |
| 30 | 140676765 |
| 31 | 223199915 |
| 32 | 351795463 |
| 33 | 550981974 |
[0,0,1,5,18,51,131,309,694,1494,3117,6320,12514, 24234,46016,85790,157301,283982,505432,887692, 1539969,2640920,4480467,7524824,12518126,20638663, 33739438,54713975,88052156,140676765,223199915, 351795463,550981974] |