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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 2 |
| 5 | 5 |
| 6 | 12 |
| 7 | 28 |
| 8 | 66 |
| 9 | 156 |
| 10 | 370 |
| 11 | 882 |
| 12 | 2112 |
| 13 | 5079 |
| 14 | 12264 |
| 15 | 29725 |
| 16 | 72298 |
| 17 | 176414 |
| 18 | 431754 |
| 19 | 1059595 |
| 20 | 2607090 |
| 21 | 6429913 |
| 22 | 15893330 |
| 23 | 39365876 |
| 24 | 97692372 |
| 25 | 242875105 |
| 26 | 604836072 |
| 27 | 1508619585 |
| 28 | 3768496102 |
| 29 | 9426815859 |
| 30 | 23612178180 |
| 31 | 59217406914 |
[0,0,0,1,2,5,12,28,66,156,370,882,2112,5079,12264, 29725,72298,176414,431754,1059595,2607090,6429913, 15893330,39365876,97692372,242875105,604836072, 1508619585,3768496102,9426815859,23612178180, 59217406914] |