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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 20 |
| 4 | 243 |
| 5 | 3104 |
| 6 | 46625 |
| 7 | 823500 |
| 8 | 16777159 |
| 9 | 387420416 |
| 10 | 9999999909 |
| 11 | 285311670500 |
| 12 | 8916100448123 |
| 13 | 302875106592096 |
| 14 | 11112006825557833 |
| 15 | 437893890380859164 |
| 16 | 18446744073709551375 |
| 17 | 827240261886336763904 |
| 18 | 39346408075296537575117 |
[1,20,243,3104,46625,823500,16777159,387420416, 9999999909,285311670500,8916100448123, 302875106592096,11112006825557833, 437893890380859164,18446744073709551375, 827240261886336763904,39346408075296537575117] |