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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 24 |
| 5 | 240 |
| 6 | 1560 |
| 7 | 8400 |
| 8 | 40824 |
| 9 | 186480 |
| 10 | 818520 |
| 11 | 3498000 |
| 12 | 14676024 |
| 13 | 60780720 |
| 14 | 249401880 |
| 15 | 1016542800 |
| 16 | 4123173624 |
| 17 | 16664094960 |
| 18 | 67171367640 |
| 19 | 270232006800 |
| 20 | 1085570781624 |
| 21 | 4356217681200 |
| 22 | 17466686971800 |
| 23 | 69992221794000 |
| 24 | 280345359228024 |
| 25 | 1122510953731440 |
[0,0,0,24,240,1560,8400,40824,186480,818520, 3498000,14676024,60780720,249401880,1016542800, 4123173624,16664094960,67171367640,270232006800, 1085570781624,4356217681200,17466686971800, 69992221794000,280345359228024,1122510953731440] |