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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 23 |
| 5 | 75 |
| 6 | 265 |
| 7 | 967 |
| 8 | 3612 |
| 9 | 13881 |
| 10 | 54146 |
| 11 | 215339 |
| 12 | 867249 |
| 13 | 3535563 |
| 14 | 14566079 |
| 15 | 60517102 |
| 16 | 253570701 |
| 17 | 1069568322 |
| 18 | 4541585236 |
| 19 | 19392943306 |
| 20 | 83243237160 |
| 21 | 359033012893 |
| 22 | 1555119755691 |
| 23 | 6763331933677 |
| 24 | 29520138529918 |
| 25 | 129292173036870 |
| 26 | 568043777594337 |
| 27 | 2503024585782289 |
| 28 | 11059575161062936 |
[1,1,3,7,23,75,265,967,3612,13881,54146,215339, 867249,3535563,14566079,60517102,253570701, 1069568322,4541585236,19392943306,83243237160, 359033012893,1555119755691,6763331933677, 29520138529918,129292173036870,568043777594337, 2503024585782289,11059575161062936] |