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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 5 |
| 3 | 15 |
| 4 | 55 |
| 5 | 140 |
| 6 | 448 |
| 7 | 1022 |
| 8 | 2710 |
| 9 | 6048 |
| 10 | 14114 |
| 11 | 28831 |
| 12 | 64091 |
| 13 | 123649 |
| 14 | 251295 |
| 15 | 476835 |
| 16 | 916972 |
| 17 | 1654044 |
| 18 | 3080159 |
| 19 | 5377431 |
| 20 | 9624588 |
| 21 | 16490017 |
| 22 | 28433473 |
| 23 | 47423409 |
| 24 | 80279375 |
[1,5,15,55,140,448,1022,2710,6048,14114,28831, 64091,123649,251295,476835,916972,1654044,3080159, 5377431,9624588,16490017,28433473,47423409, 80279375] |