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| n | a(n) |
|---|---|
| 1 | 20 |
| 2 | 400 |
| 3 | 4143 |
| 4 | 40230 |
| 5 | 342240 |
| 6 | 2800798 |
| 7 | 22015314 |
| 8 | 169875850 |
| 9 | 1291198707 |
| 10 | 9730141740 |
| 11 | 72859323174 |
| 12 | 543367409130 |
| 13 | 4040626627139 |
| 14 | 29988912453443 |
| 15 | 222268109960222 |
| 16 | 1645817547627269 |
| 17 | 12178540896840119 |
| 18 | 90075084742836021 |
[20,400,4143,40230,342240,2800798,22015314, 169875850,1291198707,9730141740,72859323174, 543367409130,4040626627139,29988912453443, 222268109960222,1645817547627269, 12178540896840119,90075084742836021] |