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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 13 |
| 4 | 59 |
| 5 | 271 |
| 6 | 1257 |
| 7 | 5881 |
| 8 | 27715 |
| 9 | 131395 |
| 10 | 626033 |
| 11 | 2995147 |
| 12 | 14380181 |
| 13 | 69249337 |
| 14 | 334345091 |
| 15 | 1617924973 |
| 16 | 7844900339 |
| 17 | 38105139907 |
| 18 | 185380469961 |
| 19 | 903147125143 |
| 20 | 4405621159969 |
| 21 | 21515837558557 |
| 22 | 105188202097091 |
| 23 | 514747668977263 |
[1,1,3,13,59,271,1257,5881,27715,131395,626033, 2995147,14380181,69249337,334345091,1617924973, 7844900339,38105139907,185380469961,903147125143, 4405621159969,21515837558557,105188202097091, 514747668977263] |