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| n | a(n) |
|---|---|
| 1 | 9 |
| 2 | 4 |
| 3 | 121 |
| 4 | 180 |
| 5 | 2041 |
| 6 | 5068 |
| 7 | 37441 |
| 8 | 121588 |
| 9 | 722009 |
| 10 | 2720828 |
| 11 | 14363985 |
| 12 | 58850116 |
| 13 | 291217929 |
| 14 | 1250645324 |
| 15 | 5970338241 |
| 16 | 26327622356 |
| 17 | 123189300217 |
| 18 | 551369047260 |
| 19 | 2551171130801 |
| 20 | 11514142774628 |
| 21 | 52942859314409 |
| 22 | 240066004887660 |
[9,4,121,180,2041,5068,37441,121588,722009, 2720828,14363985,58850116,291217929,1250645324, 5970338241,26327622356,123189300217,551369047260, 2551171130801,11514142774628,52942859314409, 240066004887660] |