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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 16 |
| 4 | 53 |
| 5 | 186 |
| 6 | 672 |
| 7 | 2465 |
| 8 | 9158 |
| 9 | 34354 |
| 10 | 129833 |
| 11 | 493534 |
| 12 | 1884955 |
| 13 | 7227522 |
| 14 | 27804584 |
| 15 | 107268790 |
| 16 | 414852381 |
| 17 | 1607836478 |
| 18 | 6243201267 |
| 19 | 24282747900 |
| 20 | 94587991975 |
| 21 | 368940451638 |
| 22 | 1440796181876 |
| 23 | 5632827891526 |
| 24 | 22043782012620 |
[1,2,5,16,53,186,672,2465,9158,34354,129833, 493534,1884955,7227522,27804584,107268790, 414852381,1607836478,6243201267,24282747900, 94587991975,368940451638,1440796181876, 5632827891526,22043782012620] |