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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 3 |
| 3 | 150 |
| 4 | 31185 |
| 5 | 12999420 |
| 6 | 9622703475 |
| 7 | 11539805487210 |
| 8 | 20981809690466625 |
| 9 | 54997428661808232600 |
| 10 | 199760599884519009411075 |
| 11 | 973866344327734952575230750 |
| 12 | 6207575427404936259602204502225 |
[0,3,150,31185,12999420,9622703475,11539805487210, 20981809690466625,54997428661808232600, 199760599884519009411075, 973866344327734952575230750, 6207575427404936259602204502225] |