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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | 102 |
| 4 | 250 |
| 5 | 5253 |
| 6 | 16478 |
| 7 | 278315 |
| 8 | 1019120 |
| 9 | 15188955 |
| 10 | 62846854 |
| 11 | 850526529 |
| 12 | 3891052774 |
| 13 | 48586797398 |
| 14 | 241642747938 |
| 15 | 2818541243728 |
| 16 | 15034216343154 |
| 17 | 165507316465985 |
| 18 | 936470483789652 |
| 19 | 9815405179117090 |
| 20 | 58379693308010828 |
[1,0,102,250,5253,16478,278315,1019120,15188955, 62846854,850526529,3891052774,48586797398, 241642747938,2818541243728,15034216343154, 165507316465985,936470483789652,9815405179117090, 58379693308010828] |