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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 2 |
| 2 | 0 |
| 3 | 2 |
| 4 | 4480 |
| 5 | 2 |
| 6 | 274560 |
| 7 | 717516802 |
| 8 | 20650240 |
| 9 | 397299302402 |
| 10 | 1260764869707520 |
| 11 | 211694311628802 |
| 12 | 3189730834295158400 |
| 13 | 12098583209553471488002 |
| 14 | 6723227372694939050880 |
[0,2,0,2,4480,2,274560,717516802,20650240, 397299302402,1260764869707520,211694311628802, 3189730834295158400,12098583209553471488002, 6723227372694939050880] |