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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 2 |
| 5 | 6 |
| 6 | 12 |
| 7 | 30 |
| 8 | 66 |
| 9 | 156 |
| 10 | 357 |
| 11 | 842 |
| 12 | 1961 |
| 13 | 4643 |
| 14 | 10960 |
| 15 | 26072 |
| 16 | 62084 |
| 17 | 148499 |
| 18 | 355784 |
| 19 | 855038 |
| 20 | 2058536 |
| 21 | 4967099 |
| 22 | 12005308 |
| 23 | 29067646 |
| 24 | 70483478 |
| 25 | 171158311 |
| 26 | 416168250 |
| 27 | 1013156687 |
| 28 | 2469301316 |
| 29 | 6024696764 |
| 30 | 14713845227 |
| 31 | 35968547836 |
| 32 | 88003373522 |
| 33 | 215493542625 |
[0,0,1,2,6,12,30,66,156,357,842,1961,4643,10960, 26072,62084,148499,355784,855038,2058536,4967099, 12005308,29067646,70483478,171158311,416168250, 1013156687,2469301316,6024696764,14713845227, 35968547836,88003373522,215493542625] |