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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 11 |
| 4 | 30 |
| 5 | 95 |
| 6 | 328 |
| 7 | 1211 |
| 8 | 4779 |
| 9 | 19902 |
| 10 | 86682 |
| 11 | 393072 |
| 12 | 1847264 |
| 13 | 8965027 |
| 14 | 44814034 |
| 15 | 230232789 |
| 16 | 1213534723 |
| 17 | 6552995689 |
| 18 | 36207886517 |
| 19 | 204499421849 |
| 20 | 1179555353219 |
| 21 | 6942908667578 |
| 22 | 41673453738272 |
| 23 | 254918441681030 |
| 24 | 1588256152307002 |
| 25 | 10073760672179505 |
[1,2,4,11,30,95,328,1211,4779,19902,86682,393072, 1847264,8965027,44814034,230232789,1213534723, 6552995689,36207886517,204499421849,1179555353219, 6942908667578,41673453738272,254918441681030, 1588256152307002,10073760672179505] |