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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | -1008 |
| 5 | -37120 |
| 6 | -473600 |
| 7 | 0 |
| 8 | 63996160 |
| 9 | 702013440 |
| 10 | 2893578240 |
| 11 | 0 |
| 12 | -393379835904 |
| 13 | -12971004067840 |
| 14 | -160377313820672 |
| 15 | 0 |
| 16 | 21792325059543040 |
| 17 | 239501351489372160 |
| 18 | 987061897553510400 |
| 19 | 0 |
| 20 | -134124249770961666048 |
| 21 | -4422152303189489090560 |
[1,0,0,0,-1008,-37120,-473600,0,63996160, 702013440,2893578240,0,-393379835904, -12971004067840,-160377313820672,0, 21792325059543040,239501351489372160, 987061897553510400,0,-134124249770961666048, -4422152303189489090560] |