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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 8 |
| 2 | 12 |
| 3 | 0 |
| 4 | 28 |
| 5 | 0 |
| 6 | 264 |
| 7 | 0 |
| 8 | 3720 |
| 9 | 0 |
| 10 | 63840 |
| 11 | 0 |
| 12 | 1232432 |
| 13 | 0 |
| 14 | 25731216 |
| 15 | 0 |
| 16 | 568130552 |
| 17 | 0 |
| 18 | 13081215840 |
| 19 | 0 |
| 20 | 311178567648 |
| 21 | 0 |
| 22 | 7597974517056 |
| 23 | 0 |
| 24 | 189518147463232 |
| 25 | 0 |
| 26 | 4811962763222784 |
| 27 | 0 |
| 28 | 124028853694440640 |
| 29 | 0 |
| 30 | 3238304402221646880 |
| 31 | 0 |
[1,8,12,0,28,0,264,0,3720,0,63840,0,1232432,0, 25731216,0,568130552,0,13081215840,0,311178567648, 0,7597974517056,0,189518147463232,0, 4811962763222784,0,124028853694440640,0, 3238304402221646880,0] |