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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 7 |
| 5 | 13 |
| 6 | 35 |
| 7 | 85 |
| 8 | 254 |
| 9 | 701 |
| 10 | 2377 |
| 11 | 7944 |
| 12 | 25220 |
| 13 | 95910 |
| 14 | 332300 |
| 15 | 1164825 |
| 16 | 4379920 |
| 17 | 16649851 |
| 18 | 58473414 |
[1,1,2,3,7,13,35,85,254,701,2377,7944,25220,95910, 332300,1164825,4379920,16649851,58473414] |