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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 15 |
| 5 | 51 |
| 6 | 186 |
| 7 | 707 |
| 8 | 2763 |
| 9 | 11024 |
| 10 | 44714 |
| 11 | 183830 |
| 12 | 764374 |
| 13 | 3209031 |
| 14 | 13584217 |
| 15 | 57918257 |
| 16 | 248502212 |
| 17 | 1072159593 |
| 18 | 4648747281 |
| 19 | 20245772943 |
| 20 | 88524364619 |
| 21 | 388469248937 |
| 22 | 1710304847176 |
| 23 | 7552480937589 |
| 24 | 33442335151831 |
| 25 | 148456424569164 |
| 26 | 660560252794208 |
[1,1,2,5,15,51,186,707,2763,11024,44714,183830, 764374,3209031,13584217,57918257,248502212, 1072159593,4648747281,20245772943,88524364619, 388469248937,1710304847176,7552480937589, 33442335151831,148456424569164,660560252794208] |