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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 2 |
| 6 | 6 |
| 7 | 15 |
| 8 | 36 |
| 9 | 91 |
| 10 | 218 |
| 11 | 544 |
| 12 | 1325 |
| 13 | 3281 |
| 14 | 8055 |
| 15 | 19880 |
| 16 | 48930 |
| 17 | 120610 |
| 18 | 297055 |
| 19 | 731922 |
| 20 | 1802994 |
| 21 | 4441915 |
| 22 | 10942602 |
| 23 | 26957739 |
| 24 | 66410994 |
| 25 | 163606230 |
| 26 | 403049273 |
| 27 | 992926975 |
| 28 | 2446110587 |
| 29 | 6026082552 |
| 30 | 14845470456 |
| 31 | 36572353012 |
| 32 | 90097307929 |
[0,0,0,1,2,6,15,36,91,218,544,1325,3281,8055, 19880,48930,120610,297055,731922,1802994,4441915, 10942602,26957739,66410994,163606230,403049273, 992926975,2446110587,6026082552,14845470456, 36572353012,90097307929] |