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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 120 |
| 2 | 945 |
| 3 | 87595 |
| 4 | 19558470 |
| 5 | 7236515981 |
| 6 | 3745777177366 |
| 7 | 2468722942369153 |
| 8 | 1953740543358042205 |
| 9 | 1785201362960729511070 |
| 10 | 1831976833971352074708780 |
| 11 | 2068976591723429552651743620 |
| 12 | 2532392303303120865350779766160 |
| 13 | 3319547855302819899374947284511390 |
[1,120,945,87595,19558470,7236515981, 3745777177366,2468722942369153, 1953740543358042205,1785201362960729511070, 1831976833971352074708780, 2068976591723429552651743620, 2532392303303120865350779766160, 3319547855302819899374947284511390] |