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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 3 |
| 7 | 10 |
| 8 | 21 |
| 9 | 36 |
| 10 | 85 |
| 11 | 291 |
| 12 | 923 |
| 13 | 3735 |
| 14 | 16127 |
| 15 | 78677 |
| 16 | 397086 |
| 17 | 2338305 |
| 18 | 14669249 |
| 19 | 110594974 |
| 20 | 880940226 |
| 21 | 8350924404 |
| 22 | 83469619311 |
| 23 | 977221485292 |
| 24 | 12070642055579 |
[1,1,1,1,1,3,10,21,36,85,291,923,3735,16127,78677, 397086,2338305,14669249,110594974,880940226, 8350924404,83469619311,977221485292, 12070642055579] |