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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 120 |
| 3 | 44121 |
| 4 | 23096640 |
| 5 | 14346274601 |
| 6 | 9859397817600 |
| 7 | 7244702262723241 |
| 8 | 5582882474985676800 |
| 9 | 4458184170040912112721 |
| 10 | 3659860624802972467991520 |
| 11 | 3071619882576430968562820921 |
| 12 | 2624927569719125879186684147520 |
| 13 | 2277214648583912948194825667564881 |
[1,120,44121,23096640,14346274601,9859397817600, 7244702262723241,5582882474985676800, 4458184170040912112721,3659860624802972467991520, 3071619882576430968562820921, 2624927569719125879186684147520, 2277214648583912948194825667564881] |