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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 120 |
| 3 | 85320 |
| 4 | 174792640 |
| 5 | 782083984500 |
| 6 | 6505247592703944 |
| 7 | 90471680541391718800 |
| 8 | 1951589337580920650595840 |
| 9 | 61742372998425082372103866380 |
| 10 | 2743355077591282538231819720749000 |
| 11 | 165382891003629711761140477728569323368 |
| 12 | 13151651360462180865959048190677701749268800 |
[1,1,120,85320,174792640,782083984500, 6505247592703944,90471680541391718800, 1951589337580920650595840, 61742372998425082372103866380, 2743355077591282538231819720749000, 165382891003629711761140477728569323368, 13151651360462180865959048190677701749268800] |