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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 6 |
| 4 | 9 |
| 5 | 31 |
| 6 | 60 |
| 7 | 169 |
| 8 | 369 |
| 9 | 954 |
| 10 | 2201 |
| 11 | 5479 |
| 12 | 12960 |
| 13 | 31721 |
| 14 | 75881 |
| 15 | 184326 |
| 16 | 443169 |
| 17 | 1072871 |
| 18 | 2585340 |
| 19 | 6249329 |
| 20 | 15074649 |
| 21 | 36413754 |
| 22 | 87877681 |
| 23 | 212208719 |
| 24 | 512231040 |
| 25 | 1236774481 |
| 26 | 2985612241 |
| 27 | 7208270406 |
| 28 | 17401713849 |
| 29 | 42012408751 |
[0,1,1,6,9,31,60,169,369,954,2201,5479,12960, 31721,75881,184326,443169,1072871,2585340,6249329, 15074649,36413754,87877681,212208719,512231040, 1236774481,2985612241,7208270406,17401713849, 42012408751] |