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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 1 |
| 7 | 54 |
| 8 | 1764 |
| 9 | 34520 |
| 10 | 495320 |
| 11 | 5794944 |
| 12 | 58753904 |
| 13 | 536362784 |
| 14 | 4522914840 |
| 15 | 35866688640 |
| 16 | 270967688256 |
| 17 | 1969261200000 |
| 18 | 13869344791528 |
| 19 | 95206279619680 |
| 20 | 639874975302480 |
| 21 | 4225823731044064 |
| 22 | 27502902905426872 |
| 23 | 176817788582956224 |
| 24 | 1125118788057967200 |
[0,0,0,0,0,0,1,54,1764,34520,495320,5794944, 58753904,536362784,4522914840,35866688640, 270967688256,1969261200000,13869344791528, 95206279619680,639874975302480,4225823731044064, 27502902905426872,176817788582956224, 1125118788057967200] |