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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 784 |
| 5 | 40496 |
| 6 | 451104 |
| 7 | 2803552 |
| 8 | 12139552 |
| 9 | 41792672 |
| 10 | 121269248 |
| 11 | 310362944 |
| 12 | 718151344 |
| 13 | 1534460624 |
| 14 | 3067048224 |
| 15 | 5801302304 |
| 16 | 10464095808 |
| 17 | 18125622336 |
| 18 | 30299632896 |
| 19 | 49104515712 |
| 20 | 77410664016 |
| 21 | 119081302128 |
| 22 | 179178580768 |
[0,0,0,784,40496,451104,2803552,12139552,41792672, 121269248,310362944,718151344,1534460624, 3067048224,5801302304,10464095808,18125622336, 30299632896,49104515712,77410664016,119081302128, 179178580768] |