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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 8 |
| 5 | 32 |
| 6 | 238 |
| 7 | 1488 |
| 8 | 9778 |
| 9 | 91628 |
| 10 | 685364 |
| 11 | 5183732 |
| 12 | 43292440 |
| 13 | 341958992 |
| 14 | 2698310688 |
| 15 | 22015262376 |
| 16 | 177423576662 |
| 17 | 1428012268840 |
| 18 | 11630157575168 |
| 19 | 94604167006872 |
| 20 | 769682941957332 |
| 21 | 6291338814803772 |
| 22 | 51481101154395306 |
[0,0,0,8,32,238,1488,9778,91628,685364,5183732, 43292440,341958992,2698310688,22015262376, 177423576662,1428012268840,11630157575168, 94604167006872,769682941957332,6291338814803772, 51481101154395306] |