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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 3 |
| 5 | 9 |
| 6 | 17 |
| 7 | 41 |
| 8 | 88 |
| 9 | 185 |
| 10 | 387 |
| 11 | 810 |
| 12 | 1669 |
| 13 | 3435 |
| 14 | 7039 |
| 15 | 14360 |
| 16 | 29225 |
| 17 | 59347 |
| 18 | 120228 |
| 19 | 243166 |
| 20 | 491085 |
| 21 | 990446 |
| 22 | 1995409 |
| 23 | 4016259 |
| 24 | 8076959 |
| 25 | 16231746 |
| 26 | 32599773 |
| 27 | 65437945 |
| 28 | 131293191 |
| 29 | 263316897 |
| 30 | 527912139 |
| 31 | 1058061751 |
| 32 | 2120039884 |
| 33 | 4246934012 |
| 34 | 8505864639 |
[0,0,0,1,3,9,17,41,88,185,387,810,1669,3435,7039, 14360,29225,59347,120228,243166,491085,990446, 1995409,4016259,8076959,16231746,32599773, 65437945,131293191,263316897,527912139,1058061751, 2120039884,4246934012,8505864639] |