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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 20 |
| 2 | 400 |
| 3 | 1862 |
| 4 | 9373 |
| 5 | 51323 |
| 6 | 298821 |
| 7 | 1965313 |
| 8 | 11759158 |
| 9 | 66434263 |
| 10 | 365037821 |
| 11 | 1895313862 |
[1,20,400,1862,9373,51323,298821,1965313,11759158, 66434263,365037821,1895313862] |