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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 1 |
| 5 | 6 |
| 6 | 9 |
| 7 | 12 |
| 8 | 41 |
| 9 | 60 |
| 10 | 121 |
| 11 | 310 |
| 12 | 505 |
| 13 | 1162 |
| 14 | 2577 |
| 15 | 4760 |
| 16 | 11089 |
| 17 | 23256 |
| 18 | 47089 |
| 19 | 107274 |
| 20 | 223345 |
| 21 | 476366 |
| 22 | 1061017 |
| 23 | 2237796 |
| 24 | 4888313 |
| 25 | 10745748 |
| 26 | 23048169 |
| 27 | 50792638 |
| 28 | 111180265 |
| 29 | 241786898 |
| 30 | 534219297 |
[1,0,1,2,1,6,9,12,41,60,121,310,505,1162,2577, 4760,11089,23256,47089,107274,223345,476366, 1061017,2237796,4888313,10745748,23048169, 50792638,111180265,241786898,534219297] |