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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 624 |
| 3 | 3456 |
| 4 | 17544 |
| 5 | 47616 |
| 6 | 130752 |
| 7 | 252672 |
| 8 | 560904 |
| 9 | 887808 |
| 10 | 1692576 |
| 11 | 2412672 |
| 12 | 4280736 |
| 13 | 5564928 |
| 14 | 9068928 |
| 15 | 11460864 |
| 16 | 17948424 |
| 17 | 21310464 |
| 18 | 32009904 |
| 19 | 37102464 |
| 20 | 54842544 |
| 21 | 61519872 |
| 22 | 87013440 |
| 23 | 96555264 |
| 24 | 136860576 |
| 25 | 146503680 |
| 26 | 200463648 |
| 27 | 216131328 |
| 28 | 294879552 |
[1,0,624,3456,17544,47616,130752,252672,560904, 887808,1692576,2412672,4280736,5564928,9068928, 11460864,17948424,21310464,32009904,37102464, 54842544,61519872,87013440,96555264,136860576, 146503680,200463648,216131328,294879552] |