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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 5 |
| 5 | 24 |
| 6 | 142 |
| 7 | 840 |
| 8 | 4919 |
| 9 | 28704 |
| 10 | 167344 |
| 11 | 975408 |
| 12 | 5685161 |
| 13 | 33135624 |
| 14 | 193128658 |
| 15 | 1125636408 |
| 16 | 6560689883 |
| 17 | 38238502992 |
| 18 | 222870328180 |
| 19 | 1298983466208 |
| 20 | 7571030469197 |
| 21 | 44127199349112 |
| 22 | 257192165625622 |
| 23 | 1499025794404776 |
[0,0,0,5,24,142,840,4919,28704,167344,975408, 5685161,33135624,193128658,1125636408,6560689883, 38238502992,222870328180,1298983466208, 7571030469197,44127199349112,257192165625622, 1499025794404776] |