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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 24 |
| 3 | 718 |
| 4 | 40040 |
| 5 | 3586122 |
| 6 | 470928612 |
| 7 | 85257985902 |
| 8 | 20354196606768 |
| 9 | 6195953068191762 |
| 10 | 2342416197502447932 |
| 11 | 1076777305129376444790 |
| 12 | 591474826398069745456200 |
| 13 | 382625479333794154176056730 |
[1,2,24,718,40040,3586122,470928612,85257985902, 20354196606768,6195953068191762, 2342416197502447932,1076777305129376444790, 591474826398069745456200, 382625479333794154176056730] |