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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 5 |
| 3 | 25 |
| 4 | 155 |
| 5 | 1080 |
| 6 | 8085 |
| 7 | 63525 |
| 8 | 516790 |
| 9 | 4315805 |
| 10 | 36786385 |
| 11 | 318736105 |
| 12 | 2799049985 |
| 13 | 24857641900 |
| 14 | 222861398060 |
| 15 | 2014418084860 |
| 16 | 18337277269475 |
| 17 | 167961106916065 |
| 18 | 1546879330598945 |
| 19 | 14315792338559005 |
| 20 | 133065134882334095 |
| 21 | 1241694764334690820 |
| 22 | 11628016504072124555 |
| 23 | 109243880617142972435 |
[0,5,25,155,1080,8085,63525,516790,4315805, 36786385,318736105,2799049985,24857641900, 222861398060,2014418084860,18337277269475, 167961106916065,1546879330598945, 14315792338559005,133065134882334095, 1241694764334690820,11628016504072124555, 109243880617142972435] |