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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 56 |
| 5 | 9013 |
| 6 | 681474 |
| 7 | 33297380 |
| 8 | 1245930065 |
| 9 | 38921113842 |
| 10 | 1063289204514 |
| 11 | 26089682147964 |
| 12 | 584494025830394 |
| 13 | 12087696271833266 |
| 14 | 232582740271181155 |
| 15 | 4188958906389785259 |
| 16 | 70966356151034388909 |
| 17 | 1135537418173238330558 |
| 18 | 17222401475699072188275 |
[0,0,0,56,9013,681474,33297380,1245930065, 38921113842,1063289204514,26089682147964, 584494025830394,12087696271833266, 232582740271181155,4188958906389785259, 70966356151034388909,1135537418173238330558, 17222401475699072188275] |