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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | 0 |
| 4 | 4 |
| 5 | 16 |
| 6 | 0 |
| 7 | 0 |
| 8 | 2080 |
| 9 | 32896 |
| 10 | 0 |
| 11 | 0 |
| 12 | 178990080 |
| 13 | 11453771776 |
| 14 | 0 |
| 15 | 0 |
| 16 | 3002404080455680 |
| 17 | 768614611824951296 |
| 18 | 0 |
| 19 | 0 |
| 20 | 10316167090130469587779584 |
| 21 | 10563755026498136326181748736 |
| 22 | 0 |
| 23 | 0 |
| 24 | 7561830376433501721102295492903043072 |
| 25 | 30973257220603971305905396442627825467392 |
[1,0,0,4,16,0,0,2080,32896,0,0,178990080, 11453771776,0,0,3002404080455680, 768614611824951296,0,0,10316167090130469587779584, 10563755026498136326181748736,0,0, 7561830376433501721102295492903043072, 30973257220603971305905396442627825467392] |