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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 14 |
| 5 | 41 |
| 6 | 125 |
| 7 | 393 |
| 8 | 1265 |
| 9 | 4147 |
| 10 | 13799 |
| 11 | 46488 |
| 12 | 158261 |
| 13 | 543610 |
| 14 | 1881730 |
| 15 | 6557818 |
| 16 | 22990323 |
| 17 | 81026013 |
| 18 | 286915275 |
| 19 | 1020294605 |
| 20 | 3642192301 |
| 21 | 13047053600 |
| 22 | 46885795710 |
| 23 | 168979132425 |
| 24 | 610640337099 |
| 25 | 2212116899436 |
| 26 | 8031940264223 |
| 27 | 29224761233788 |
[1,1,2,5,14,41,125,393,1265,4147,13799,46488, 158261,543610,1881730,6557818,22990323,81026013, 286915275,1020294605,3642192301,13047053600, 46885795710,168979132425,610640337099, 2212116899436,8031940264223,29224761233788] |