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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 16 |
| 4 | 57 |
| 5 | 210 |
| 6 | 781 |
| 7 | 2912 |
| 8 | 10865 |
| 9 | 40546 |
| 10 | 151317 |
| 11 | 564720 |
| 12 | 2107561 |
| 13 | 7865522 |
| 14 | 29354525 |
| 15 | 109552576 |
| 16 | 408855777 |
| 17 | 1525870530 |
| 18 | 5694626341 |
| 19 | 21252634832 |
| 20 | 79315912985 |
| 21 | 296011017106 |
| 22 | 1104728155437 |
| 23 | 4122901604640 |
| 24 | 15386878263121 |
[1,2,5,16,57,210,781,2912,10865,40546,151317, 564720,2107561,7865522,29354525,109552576, 408855777,1525870530,5694626341,21252634832, 79315912985,296011017106,1104728155437, 4122901604640,15386878263121] |