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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 10 |
| 3 | 75 |
| 4 | 758 |
| 5 | 9660 |
| 6 | 148772 |
| 7 | 2688420 |
| 8 | 55784710 |
| 9 | 1307378358 |
| 10 | 34158527852 |
| 11 | 984547901051 |
| 12 | 31034429035260 |
| 13 | 1062081192039140 |
| 14 | 39218355263626632 |
| 15 | 1554260970293874135 |
| 16 | 65803396940022289734 |
| 17 | 2964120950479432183950 |
| 18 | 141548149894016562758300 |
| 19 | 7143010414313948156920665 |
| 20 | 379821534884560034711455956 |
[1,2,10,75,758,9660,148772,2688420,55784710, 1307378358,34158527852,984547901051, 31034429035260,1062081192039140,39218355263626632, 1554260970293874135,65803396940022289734, 2964120950479432183950,141548149894016562758300, 7143010414313948156920665, 379821534884560034711455956] |