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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 16 |
| 5 | 53 |
| 6 | 201 |
| 7 | 751 |
| 8 | 2969 |
| 9 | 11912 |
| 10 | 48722 |
| 11 | 202963 |
| 12 | 857651 |
| 13 | 3662901 |
| 14 | 15846173 |
| 15 | 69089287 |
| 16 | 303942174 |
| 17 | 1346846163 |
| 18 | 6005971987 |
| 19 | 26944569704 |
| 20 | 121509650966 |
| 21 | 550564330442 |
| 22 | 2505673556481 |
| 23 | 11448107083346 |
| 24 | 52497934562648 |
| 25 | 241548938785273 |
| 26 | 1114836139179427 |
| 27 | 5160272351336388 |
| 28 | 23949236821028822 |
[1,1,2,5,16,53,201,751,2969,11912,48722,202963, 857651,3662901,15846173,69089287,303942174, 1346846163,6005971987,26944569704,121509650966, 550564330442,2505673556481,11448107083346, 52497934562648,241548938785273,1114836139179427, 5160272351336388,23949236821028822] |