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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 11 |
| 5 | 45 |
| 6 | 195 |
| 7 | 885 |
| 8 | 4151 |
| 9 | 19963 |
| 10 | 97899 |
| 11 | 487717 |
| 12 | 2461393 |
| 13 | 12557439 |
| 14 | 64657461 |
| 15 | 335562499 |
| 16 | 1753538133 |
| 17 | 9218852525 |
| 18 | 48725353661 |
| 19 | 258759350495 |
| 20 | 1380021781719 |
| 21 | 7388261669161 |
| 22 | 39692491630271 |
| 23 | 213918652593929 |
[1,1,3,11,45,195,885,4151,19963,97899,487717, 2461393,12557439,64657461,335562499,1753538133, 9218852525,48725353661,258759350495,1380021781719, 7388261669161,39692491630271,213918652593929] |