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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 800 |
| 2 | 107200 |
| 3 | 5831520 |
| 4 | 174074240 |
| 5 | 3339504032 |
| 6 | 45443741760 |
| 7 | 469398016480 |
| 8 | 3866465104640 |
| 9 | 26364054632480 |
| 10 | 153196621856192 |
| 11 | 776310358810720 |
| 12 | 3494968152620160 |
| 13 | 14192829714542240 |
| 14 | 52645836542006080 |
| 15 | 180251314603984608 |
| 16 | 574703679819998720 |
| 17 | 1719149109983644960 |
| 18 | 4855892247909603520 |
[1,800,107200,5831520,174074240,3339504032, 45443741760,469398016480,3866465104640, 26364054632480,153196621856192,776310358810720, 3494968152620160,14192829714542240, 52645836542006080,180251314603984608, 574703679819998720,1719149109983644960, 4855892247909603520] |