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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 4 |
| 2 | 116 |
| 3 | 3144 |
| 4 | 84904 |
| 5 | 2292428 |
| 6 | 61895580 |
| 7 | 1671180688 |
| 8 | 45121878608 |
| 9 | 1218290722452 |
| 10 | 32893849506244 |
| 11 | 888133936668632 |
| 12 | 23979616290053112 |
| 13 | 647449639831434076 |
| 14 | 17481140275448720108 |
| 15 | 471990787437115442976 |
| 16 | 12743751260802116960416 |
| 17 | 344081284041657157931300 |
[0,4,116,3144,84904,2292428,61895580,1671180688, 45121878608,1218290722452,32893849506244, 888133936668632,23979616290053112, 647449639831434076,17481140275448720108, 471990787437115442976,12743751260802116960416, 344081284041657157931300] |