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| n | a(n) |
|---|---|
| 1 | 40 |
| 2 | 1600 |
| 3 | 13230 |
| 4 | 80511 |
| 5 | 417425 |
| 6 | 1726758 |
| 7 | 6835345 |
| 8 | 24832818 |
| 9 | 86006178 |
| 10 | 290773660 |
| 11 | 952221873 |
| 12 | 3079379225 |
| 13 | 9827714792 |
| 14 | 31055966425 |
| 15 | 97631157960 |
| 16 | 305161540736 |
| 17 | 950767241358 |
| 18 | 2954422566171 |
| 19 | 9160209168881 |
| 20 | 28362651790230 |
| 21 | 87706947406905 |
[40,1600,13230,80511,417425,1726758,6835345, 24832818,86006178,290773660,952221873,3079379225, 9827714792,31055966425,97631157960,305161540736, 950767241358,2954422566171,9160209168881, 28362651790230,87706947406905] |