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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 14 |
| 3 | 222 |
| 4 | 6384 |
| 5 | 291720 |
| 6 | 19445040 |
| 7 | 1781750880 |
| 8 | 214899027840 |
| 9 | 33007837322880 |
| 10 | 6290830003852800 |
| 11 | 1456812592995513600 |
| 12 | 402910665227270323200 |
| 13 | 131173228963370155161600 |
| 14 | 49656810289225281849907200 |
| 15 | 21628258853895305337293568000 |
| 16 | 10739534026001485514941587456000 |
[1,2,14,222,6384,291720,19445040,1781750880, 214899027840,33007837322880,6290830003852800, 1456812592995513600,402910665227270323200, 131173228963370155161600, 49656810289225281849907200, 21628258853895305337293568000, 10739534026001485514941587456000] |