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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | -24 |
| 4 | 624 |
| 5 | -23040 |
| 6 | 1102848 |
| 7 | -63320064 |
| 8 | 4204118016 |
| 9 | -315301920768 |
| 10 | 26294301622272 |
| 11 | -2410825799172096 |
| 12 | 240940701368451072 |
| 13 | -26069519382431662080 |
| 14 | 3036630253199488450560 |
| 15 | -378975438359301231476736 |
| 16 | 50464427995254851962404864 |
| 17 | -7143619061783407156694876160 |
| 18 | 1071471673355571318056420376576 |
| 19 | -169778310385940944720470768353280 |
| 20 | 28343313796900390128748827210940416 |
| 21 | -4972974647067348293267827631390195712 |
[1,3,-24,624,-23040,1102848,-63320064,4204118016, -315301920768,26294301622272,-2410825799172096, 240940701368451072,-26069519382431662080, 3036630253199488450560,-378975438359301231476736, 50464427995254851962404864, -7143619061783407156694876160, 1071471673355571318056420376576, -169778310385940944720470768353280, 28343313796900390128748827210940416, -4972974647067348293267827631390195712] |