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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 18 |
| 5 | 58 |
| 6 | 194 |
| 7 | 670 |
| 8 | 2370 |
| 9 | 8546 |
| 10 | 31298 |
| 11 | 116102 |
| 12 | 435346 |
| 13 | 1647418 |
| 14 | 6283394 |
| 15 | 24130174 |
| 16 | 93226242 |
| 17 | 362098050 |
| 18 | 1413098370 |
| 19 | 5538138182 |
| 20 | 21788069266 |
| 21 | 86016385274 |
| 22 | 340655956802 |
| 23 | 1353023683486 |
| 24 | 5388230857538 |
| 25 | 21510345134178 |
[1,1,2,6,18,58,194,670,2370,8546,31298,116102, 435346,1647418,6283394,24130174,93226242, 362098050,1413098370,5538138182,21788069266, 86016385274,340655956802,1353023683486, 5388230857538,21510345134178] |