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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 13 |
| 5 | 63 |
| 6 | 330 |
| 7 | 1838 |
| 8 | 10758 |
| 9 | 65586 |
| 10 | 413639 |
| 11 | 2684469 |
| 12 | 17852715 |
| 13 | 121256457 |
| 14 | 838843641 |
| 15 | 5897455515 |
| 16 | 42058344077 |
| 17 | 303787163823 |
| 18 | 2219452035639 |
| 19 | 16383022072549 |
| 20 | 122066094872139 |
| 21 | 917245868993865 |
| 22 | 6946236553301334 |
| 23 | 52979616083094066 |
| 24 | 406741647662973594 |
[1,1,3,13,63,330,1838,10758,65586,413639,2684469, 17852715,121256457,838843641,5897455515, 42058344077,303787163823,2219452035639, 16383022072549,122066094872139,917245868993865, 6946236553301334,52979616083094066, 406741647662973594] |