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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 3 |
| 6 | 7 |
| 7 | 12 |
| 8 | 30 |
| 9 | 64 |
| 10 | 177 |
| 11 | 457 |
| 12 | 1403 |
| 13 | 4327 |
| 14 | 15024 |
| 15 | 54730 |
| 16 | 219311 |
| 17 | 942908 |
| 18 | 4426513 |
| 19 | 22525015 |
| 20 | 124896794 |
| 21 | 752933593 |
| 22 | 4938212176 |
| 23 | 35190683416 |
| 24 | 272266028155 |
| 25 | 2284292635109 |
[1,1,1,2,3,7,12,30,64,177,457,1403,4327,15024, 54730,219311,942908,4426513,22525015,124896794, 752933593,4938212176,35190683416,272266028155, 2284292635109] |