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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 2 |
| 3 | -3 |
| 4 | 12 |
| 5 | -40 |
| 6 | 190 |
| 7 | -1071 |
| 8 | 7224 |
| 9 | -56232 |
| 10 | 495898 |
| 11 | -4880755 |
| 12 | 53005700 |
| 13 | -629398848 |
| 14 | 8110146070 |
| 15 | -112690225935 |
| 16 | 1679413757168 |
| 17 | -26719024870576 |
| 18 | 451969255722162 |
| 19 | -8099650628337987 |
| 20 | 153288815339260796 |
[0,0,2,-3,12,-40,190,-1071,7224,-56232,495898, -4880755,53005700,-629398848,8110146070, -112690225935,1679413757168,-26719024870576, 451969255722162,-8099650628337987, 153288815339260796] |