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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 21 |
| 5 | 53 |
| 6 | 135 |
| 7 | 346 |
| 8 | 886 |
| 9 | 2266 |
| 10 | 5796 |
| 11 | 14828 |
| 12 | 37935 |
| 13 | 97047 |
| 14 | 248269 |
| 15 | 635134 |
| 16 | 1624833 |
| 17 | 4156729 |
| 18 | 10633949 |
| 19 | 27204296 |
| 20 | 69595384 |
| 21 | 178042372 |
| 22 | 455476844 |
| 23 | 1165223500 |
| 24 | 2980932677 |
| 25 | 7625970145 |
| 26 | 19509135875 |
| 27 | 49909241100 |
| 28 | 127680301337 |
| 29 | 326638093273 |
| 30 | 835621805859 |
[1,1,3,8,21,53,135,346,886,2266,5796,14828,37935, 97047,248269,635134,1624833,4156729,10633949, 27204296,69595384,178042372,455476844,1165223500, 2980932677,7625970145,19509135875,49909241100, 127680301337,326638093273,835621805859] |