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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 28 |
| 4 | 410 |
| 5 | 8386 |
| 6 | 220962 |
| 7 | 7140736 |
| 8 | 273712896 |
| 9 | 12146997564 |
| 10 | 612813677300 |
| 11 | 34647736132384 |
| 12 | 2170381958609592 |
| 13 | 149223874286440552 |
| 14 | 11173356309069883320 |
| 15 | 905099760309260722560 |
| 16 | 78870011549256151244288 |
| 17 | 7356892186010414244194704 |
| 18 | 731435433368215011644979504 |
| 19 | 77216368897429504869064200256 |
| 20 | 8626428901029156775683110378400 |
| 21 | 1016792561657783042048699052986016 |
[1,1,3,28,410,8386,220962,7140736,273712896, 12146997564,612813677300,34647736132384, 2170381958609592,149223874286440552, 11173356309069883320,905099760309260722560, 78870011549256151244288,7356892186010414244194704, 731435433368215011644979504, 77216368897429504869064200256, 8626428901029156775683110378400, 1016792561657783042048699052986016] |