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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 1 |
| 7 | 5 |
| 8 | 13 |
| 9 | 31 |
| 10 | 111 |
| 11 | 377 |
| 12 | 1545 |
| 13 | 10231 |
| 14 | 72633 |
| 15 | 559663 |
| 16 | 5155711 |
| 17 | 55582209 |
| 18 | 698619471 |
| 19 | 11001973207 |
| 20 | 206072905483 |
| 21 | 4521907343165 |
| 22 | 116328599746355 |
| 23 | 3545239477906611 |
| 24 | 127491366766265465 |
[1,1,1,1,1,1,5,13,31,111,377,1545,10231,72633, 559663,5155711,55582209,698619471,11001973207, 206072905483,4521907343165,116328599746355, 3545239477906611,127491366766265465] |