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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 2211 |
| 3 | 5151 |
| 4 | 1107816 |
| 5 | 20959575 |
| 6 | 4237107540 |
| 7 | 1564279847151 |
| 8 | 61066162885575 |
| 9 | 2533192954461975 |
| 10 | 2774988107938203 |
| 11 | 90728963274006291 |
| 12 | 18765679728507154152720 |
[0,2211,5151,1107816,20959575,4237107540, 1564279847151,61066162885575,2533192954461975, 2774988107938203,90728963274006291, 18765679728507154152720] |