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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 12 |
| 3 | 105 |
| 4 | 1308 |
| 5 | 21375 |
| 6 | 441018 |
| 7 | 10896123 |
| 8 | 315264792 |
| 9 | 10449447579 |
| 10 | 390569672910 |
| 11 | 16257117737223 |
| 12 | 745842771924660 |
| 13 | 37396841181068343 |
| 14 | 2034701509480503906 |
| 15 | 119398947940954110915 |
| 16 | 7517149983020119420848 |
| 17 | 505442237612562154098099 |
| 18 | 36150074712773275030075926 |
[1,3,12,105,1308,21375,441018,10896123,315264792, 10449447579,390569672910,16257117737223, 745842771924660,37396841181068343, 2034701509480503906,119398947940954110915, 7517149983020119420848,505442237612562154098099, 36150074712773275030075926] |