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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 5 |
| 5 | 21 |
| 6 | 31 |
| 7 | 113 |
| 8 | 177 |
| 9 | 766 |
| 10 | 1271 |
| 11 | 4687 |
| 12 | 7999 |
| 13 | 34412 |
| 14 | 60166 |
| 15 | 225891 |
| 16 | 401201 |
| 17 | 1702653 |
| 18 | 3064183 |
| 19 | 11646431 |
| 20 | 21171246 |
| 21 | 88894429 |
| 22 | 162966750 |
| 23 | 624746839 |
| 24 | 1153324813 |
| 25 | 4805206256 |
| 26 | 8923870307 |
| 27 | 34421146489 |
| 28 | 64252106507 |
| 29 | 266183327326 |
[1,1,4,5,21,31,113,177,766,1271,4687,7999,34412, 60166,225891,401201,1702653,3064183,11646431, 21171246,88894429,162966750,624746839,1153324813, 4805206256,8923870307,34421146489,64252106507, 266183327326] |