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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 22 |
| 4 | 233 |
| 5 | 3716 |
| 6 | 77257 |
| 7 | 2026606 |
| 8 | 63726497 |
| 9 | 2333516392 |
| 10 | 97335801521 |
| 11 | 4543398147674 |
| 12 | 234240366949921 |
| 13 | 13191513757571644 |
| 14 | 804299893048589225 |
| 15 | 52696560194440470046 |
| 16 | 3686739789058021079873 |
| 17 | 273950438842854064788560 |
| 18 | 21522076959435116533294177 |
[1,1,3,22,233,3716,77257,2026606,63726497, 2333516392,97335801521,4543398147674, 234240366949921,13191513757571644, 804299893048589225,52696560194440470046, 3686739789058021079873,273950438842854064788560, 21522076959435116533294177] |