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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 16 |
| 4 | 119 |
| 5 | 916 |
| 6 | 7079 |
| 7 | 54431 |
| 8 | 430016 |
| 9 | 3484767 |
| 10 | 28764495 |
| 11 | 241298621 |
| 12 | 2052293026 |
| 13 | 17663498098 |
| 14 | 153590992984 |
| 15 | 1347587381486 |
| 16 | 11917605558274 |
| 17 | 106139298948562 |
| 18 | 951243890034661 |
[0,0,16,119,916,7079,54431,430016,3484767, 28764495,241298621,2052293026,17663498098, 153590992984,1347587381486,11917605558274, 106139298948562,951243890034661] |