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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 123 |
| 3 | 140 |
| 4 | 1518 |
| 5 | 8869 |
| 6 | 61254 |
| 7 | 404761 |
| 8 | 2822737 |
| 9 | 19107381 |
| 10 | 133223036 |
| 11 | 940543590 |
| 12 | 6607193483 |
| 13 | 46568712258 |
| 14 | 329320886502 |
| 15 | 2326854046675 |
| 16 | 16446895955352 |
| 17 | 116374820631423 |
| 18 | 823487172775195 |
| 19 | 5827287415111296 |
| 20 | 41246655697979835 |
[1,123,140,1518,8869,61254,404761,2822737, 19107381,133223036,940543590,6607193483, 46568712258,329320886502,2326854046675, 16446895955352,116374820631423,823487172775195, 5827287415111296,41246655697979835] |