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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 28 |
| 5 | 79 |
| 6 | 350 |
| 7 | 1075 |
| 8 | 5020 |
| 9 | 16180 |
| 10 | 78023 |
| 11 | 259417 |
| 12 | 1278340 |
| 13 | 4343642 |
| 14 | 21740636 |
| 15 | 75065787 |
| 16 | 380161308 |
| 17 | 1328887420 |
| 18 | 6792111260 |
| 19 | 23975385148 |
| 20 | 123448657904 |
| 21 | 439228736887 |
| 22 | 2275311657814 |
| 23 | 8148868193557 |
| 24 | 42427160829508 |
[1,1,3,7,28,79,350,1075,5020,16180,78023,259417, 1278340,4343642,21740636,75065787,380161308, 1328887420,6792111260,23975385148,123448657904, 439228736887,2275311657814,8148868193557, 42427160829508] |