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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 3 |
| 4 | 9 |
| 5 | 27 |
| 6 | 83 |
| 7 | 211 |
| 8 | 522 |
| 9 | 1222 |
| 10 | 2874 |
| 11 | 6496 |
| 12 | 14593 |
| 13 | 32185 |
| 14 | 70423 |
| 15 | 153024 |
| 16 | 330195 |
| 17 | 708933 |
| 18 | 1514821 |
| 19 | 3224134 |
| 20 | 6836547 |
| 21 | 14455648 |
| 22 | 30475210 |
| 23 | 64096487 |
| 24 | 134493519 |
| 25 | 281642590 |
| 26 | 588642240 |
| 27 | 1228160742 |
| 28 | 2558300338 |
| 29 | 5321065857 |
| 30 | 11051923912 |
| 31 | 22925167566 |
[0,0,0,3,9,27,83,211,522,1222,2874,6496,14593, 32185,70423,153024,330195,708933,1514821,3224134, 6836547,14455648,30475210,64096487,134493519, 281642590,588642240,1228160742,2558300338, 5321065857,11051923912,22925167566] |