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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 21 |
| 5 | 274 |
| 6 | 5806 |
| 7 | 182766 |
| 8 | 8034916 |
| 9 | 471517614 |
| 10 | 35682799508 |
| 11 | 3388864405941 |
| 12 | 395127873991296 |
| 13 | 55543575452873070 |
| 14 | 9271180003481197642 |
| 15 | 1813921568747948684475 |
| 16 | 411378931233397975750296 |
[1,1,1,3,21,274,5806,182766,8034916,471517614, 35682799508,3388864405941,395127873991296, 55543575452873070,9271180003481197642, 1813921568747948684475,411378931233397975750296] |