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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 14 |
| 4 | 146 |
| 5 | 2602 |
| 6 | 71412 |
| 7 | 2675724 |
| 8 | 134269158 |
| 9 | 8747088662 |
| 10 | 717107850956 |
| 11 | 72007758701716 |
| 12 | 8736187050160132 |
| 13 | 1258160557017484564 |
| 14 | 212232765513231245096 |
| 15 | 41518913481377118146520 |
| 16 | 9309797624034705006898470 |
| 17 | 2374942651509463493006400390 |
| 18 | 683620331016710787068868581580 |
[1,1,2,14,146,2602,71412,2675724,134269158, 8747088662,717107850956,72007758701716, 8736187050160132,1258160557017484564, 212232765513231245096,41518913481377118146520, 9309797624034705006898470, 2374942651509463493006400390, 683620331016710787068868581580] |