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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 6 |
| 4 | -36 |
| 5 | 210 |
| 6 | -990 |
| 7 | 2184 |
| 8 | 37128 |
| 9 | -863736 |
| 10 | 13020480 |
| 11 | -168384744 |
| 12 | 1940801544 |
| 13 | -18825129648 |
| 14 | 107706637584 |
| 15 | 1386022834944 |
| 16 | -73429347222720 |
| 17 | 2034345021802560 |
| 18 | -46869707752067520 |
| 19 | 976421492688165120 |
| 20 | -18675350766042871680 |
| 21 | 319467427583225518080 |
[1,0,0,6,-36,210,-990,2184,37128,-863736,13020480, -168384744,1940801544,-18825129648,107706637584, 1386022834944,-73429347222720,2034345021802560, -46869707752067520,976421492688165120, -18675350766042871680,319467427583225518080] |