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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 54 |
| 6 | 767 |
| 7 | 10194 |
| 8 | 114028 |
| 9 | 1171524 |
| 10 | 11593345 |
| 11 | 112117864 |
| 12 | 1069300358 |
| 13 | 10109375268 |
| 14 | 95086492066 |
| 15 | 891766724342 |
| 16 | 8351325770872 |
| 17 | 78171510043913 |
| 18 | 731828924318516 |
[0,0,0,1,54,767,10194,114028,1171524,11593345, 112117864,1069300358,10109375268,95086492066, 891766724342,8351325770872,78171510043913, 731828924318516] |