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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 13 |
| 4 | 60 |
| 5 | 326 |
| 6 | 1345 |
| 7 | 6228 |
| 8 | 29845 |
| 9 | 143899 |
| 10 | 732765 |
| 11 | 3412167 |
| 12 | 16623175 |
| 13 | 81624325 |
| 14 | 400892932 |
| 15 | 2018593583 |
| 16 | 9773821243 |
| 17 | 48292202375 |
| 18 | 239383150209 |
| 19 | 1186254809797 |
| 20 | 5960931333905 |
| 21 | 29322695430795 |
| 22 | 145800954979162 |
| 23 | 726137079681765 |
| 24 | 3616351096084351 |
[1,1,3,13,60,326,1345,6228,29845,143899,732765, 3412167,16623175,81624325,400892932,2018593583, 9773821243,48292202375,239383150209,1186254809797, 5960931333905,29322695430795,145800954979162, 726137079681765,3616351096084351] |