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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 44 |
| 4 | 1025 |
| 5 | 41693 |
| 6 | 2617128 |
| 7 | 234091692 |
| 8 | 28251572652 |
| 9 | 4421489003700 |
| 10 | 870650503128708 |
| 11 | 210629395976568828 |
| 12 | 61405707768736724472 |
| 13 | 21231253444779700476672 |
| 14 | 8589776776743377081599500 |
| 15 | 4020181599664131540547091076 |
| 16 | 2155088041310451318611119556661 |
[1,1,4,44,1025,41693,2617128,234091692, 28251572652,4421489003700,870650503128708, 210629395976568828,61405707768736724472, 21231253444779700476672,8589776776743377081599500, 4020181599664131540547091076, 2155088041310451318611119556661] |