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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 17 |
| 5 | 59 |
| 6 | 265 |
| 7 | 1095 |
| 8 | 6342 |
| 9 | 33966 |
| 10 | 219968 |
| 11 | 1333654 |
| 12 | 9930505 |
| 13 | 70419371 |
[1,2,5,17,59,265,1095,6342,33966,219968,1333654, 9930505,70419371] |