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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 12 |
| 5 | 44 |
| 6 | 158 |
| 7 | 564 |
| 8 | 2010 |
| 9 | 7160 |
| 10 | 25502 |
| 11 | 90828 |
| 12 | 323490 |
| 13 | 1152128 |
| 14 | 4103366 |
| 15 | 14614356 |
| 16 | 52049802 |
| 17 | 185378120 |
| 18 | 660233966 |
| 19 | 2351458140 |
| 20 | 8374842354 |
| 21 | 29827443344 |
| 22 | 106232014742 |
| 23 | 378350930916 |
| 24 | 1347516822234 |
| 25 | 4799252328536 |
| 26 | 17092790630078 |
[1,1,3,12,44,158,564,2010,7160,25502,90828,323490, 1152128,4103366,14614356,52049802,185378120, 660233966,2351458140,8374842354,29827443344, 106232014742,378350930916,1347516822234, 4799252328536,17092790630078] |