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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 240 |
| 8 | 4200 |
| 9 | 39424 |
| 10 | 359520 |
| 11 | 3340800 |
| 12 | 32630400 |
| 13 | 331499520 |
| 14 | 3503385600 |
| 15 | 38504294400 |
| 16 | 386486100000 |
| 17 | 4064835174400 |
| 18 | 44847772569600 |
| 19 | 530121646080000 |
| 20 | 6258102529536000 |
| 21 | 78618109870080000 |
| 22 | 1027628834918400000 |
| 23 | 14504975258222592000 |
[0,0,0,0,0,0,0,240,4200,39424,359520,3340800, 32630400,331499520,3503385600,38504294400, 386486100000,4064835174400,44847772569600, 530121646080000,6258102529536000, 78618109870080000,1027628834918400000, 14504975258222592000] |