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| n | a(n) |
|---|---|
| 1 | 20 |
| 2 | 944 |
| 3 | 49564 |
| 4 | 2753720 |
| 5 | 157871240 |
| 6 | 9233006540 |
| 7 | 547490880980 |
| 8 | 32795094564080 |
| 9 | 1979734520212192 |
| 10 | 120244316085073616 |
| 11 | 7339672750101339356 |
| 12 | 449852213026938118560 |
| 13 | 27666867082225970134160 |
[20,944,49564,2753720,157871240,9233006540, 547490880980,32795094564080,1979734520212192, 120244316085073616,7339672750101339356, 449852213026938118560,27666867082225970134160] |