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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 15 |
| 4 | 65 |
| 5 | 175 |
| 6 | 1155 |
| 7 | 7229 |
| 8 | 31081 |
| 9 | 162755 |
| 10 | 1018195 |
| 11 | 5448645 |
| 12 | 28879019 |
| 13 | 171229541 |
| 14 | 991796825 |
| 15 | 5540516759 |
| 16 | 32232757569 |
| 17 | 190448140543 |
| 18 | 1105001828111 |
| 19 | 6463178610505 |
| 20 | 38380301015595 |
| 21 | 227218808375165 |
| 22 | 1344777832158545 |
| 23 | 8022879439995215 |
| 24 | 47988823484272835 |
[1,1,1,15,65,175,1155,7229,31081,162755,1018195, 5448645,28879019,171229541,991796825,5540516759, 32232757569,190448140543,1105001828111, 6463178610505,38380301015595,227218808375165, 1344777832158545,8022879439995215, 47988823484272835] |