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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 1 |
| 4 | 13 |
| 5 | 9 |
| 6 | 85 |
| 7 | 177 |
| 8 | 477 |
| 9 | 921 |
| 10 | 1701 |
| 11 | 4289 |
| 12 | 9389 |
| 13 | 28201 |
| 14 | 60917 |
| 15 | 153041 |
| 16 | 308349 |
| 17 | 733625 |
| 18 | 1645125 |
| 19 | 4062177 |
| 20 | 9670989 |
| 21 | 22625865 |
| 22 | 52288405 |
| 23 | 118067953 |
| 24 | 276204317 |
| 25 | 639640537 |
| 26 | 1523941861 |
[1,1,5,1,13,9,85,177,477,921,1701,4289,9389,28201, 60917,153041,308349,733625,1645125,4062177, 9670989,22625865,52288405,118067953,276204317, 639640537,1523941861] |