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| n | a(n) |
|---|---|
| 1 | 20 |
| 2 | 2864 |
| 3 | 93384 |
| 4 | 1332504 |
| 5 | 11215276 |
| 6 | 65834856 |
| 7 | 298220320 |
| 8 | 1112201376 |
| 9 | 3567226068 |
| 10 | 10145447312 |
| 11 | 26161729352 |
| 12 | 62193634776 |
| 13 | 138055565388 |
| 14 | 289022674792 |
| 15 | 575229575808 |
| 16 | 1095429860608 |
| 17 | 2006608664532 |
| 18 | 3551295564720 |
| 19 | 6094832640776 |
[20,2864,93384,1332504,11215276,65834856, 298220320,1112201376,3567226068,10145447312, 26161729352,62193634776,138055565388,289022674792, 575229575808,1095429860608,2006608664532, 3551295564720,6094832640776] |