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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 12 |
| 5 | 82 |
| 6 | 732 |
| 7 | 8801 |
| 8 | 125970 |
| 9 | 2230928 |
| 10 | 50152660 |
| 11 | 1253503063 |
| 12 | 37668721496 |
| 13 | 1278362451795 |
| 14 | 46557869507722 |
| 15 | 1874663971306376 |
| 16 | 85535849021496180 |
| 17 | 4369909886714119634 |
| 18 | 234108545627558824317 |
| 19 | 13835073153310329323730 |
[1,1,3,12,82,732,8801,125970,2230928,50152660, 1253503063,37668721496,1278362451795, 46557869507722,1874663971306376,85535849021496180, 4369909886714119634,234108545627558824317, 13835073153310329323730] |