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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 1 |
| 7 | 1 |
| 8 | 1 |
| 9 | 1 |
| 10 | 4 |
| 11 | 7 |
| 12 | 31 |
| 13 | 223 |
| 14 | 6943 |
| 15 | 1548511 |
| 16 | 10751318815 |
| 17 | 16648535451082975 |
| 18 | 178993712437422911994993439 |
| 19 | 744995791758846743179449146618806505170999 |
| 20 | 19049937502453316579424394593659892304405504872785268490952081866996 |
[1,1,1,1,1,1,1,1,1,4,7,31,223,6943,1548511, 10751318815,16648535451082975, 178993712437422911994993439, 744995791758846743179449146618806505170999, 19049937502453316579424394593659892304405504872785\ 268490952081866996] |