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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 20 |
| 3 | 392 |
| 4 | 11664 |
| 5 | 468512 |
| 6 | 23762752 |
| 7 | 1458000000 |
| 8 | 105046700288 |
| 9 | 8695584276992 |
| 10 | 813342767698944 |
| 11 | 84841494965553152 |
| 12 | 9765625000000000000 |
| 13 | 1229575252353016799232 |
| 14 | 168110140833113738264576 |
| 15 | 24803538869315053824278528 |
| 16 | 3928158732213644200735997952 |
| 17 | 664658611392020000000000000000 |
[1,2,20,392,11664,468512,23762752,1458000000, 105046700288,8695584276992,813342767698944, 84841494965553152,9765625000000000000, 1229575252353016799232,168110140833113738264576, 24803538869315053824278528, 3928158732213644200735997952, 664658611392020000000000000000] |