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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 34 |
| 3 | 324 |
| 4 | 1916 |
| 5 | 12318 |
| 6 | 71290 |
| 7 | 396185 |
| 8 | 2143364 |
| 9 | 11250451 |
| 10 | 57853036 |
| 11 | 292724002 |
| 12 | 1458437418 |
| 13 | 7182757280 |
| 14 | 35002131964 |
| 15 | 169019645294 |
| 16 | 809806421452 |
| 17 | 3852574230183 |
| 18 | 18214915308180 |
| 19 | 85640566518922 |
| 20 | 400632266290872 |
[0,34,324,1916,12318,71290,396185,2143364, 11250451,57853036,292724002,1458437418,7182757280, 35002131964,169019645294,809806421452, 3852574230183,18214915308180,85640566518922, 400632266290872] |