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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 0 |
| 3 | 4 |
| 4 | -12 |
| 5 | 91 |
| 6 | -660 |
| 7 | 5902 |
| 8 | -59528 |
| 9 | 677353 |
| 10 | -8557560 |
| 11 | 118927656 |
| 12 | -1802780100 |
| 13 | 29602064259 |
| 14 | -523414634652 |
| 15 | 9915150539946 |
| 16 | -200333301044880 |
| 17 | 4300435439719377 |
| 18 | -97740817953852528 |
| 19 | 2344794532033126188 |
[0,1,0,4,-12,91,-660,5902,-59528,677353,-8557560, 118927656,-1802780100,29602064259,-523414634652, 9915150539946,-200333301044880,4300435439719377, -97740817953852528,2344794532033126188] |