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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 3 |
| 5 | 7 |
| 6 | 21 |
| 7 | 43 |
| 8 | 129 |
| 9 | 259 |
| 10 | 777 |
| 11 | 1555 |
| 12 | 4665 |
| 13 | 9331 |
| 14 | 27993 |
| 15 | 55987 |
| 16 | 167961 |
| 17 | 335923 |
| 18 | 1007769 |
| 19 | 2015539 |
| 20 | 6046617 |
| 21 | 12093235 |
| 22 | 36279705 |
| 23 | 72559411 |
| 24 | 217678233 |
| 25 | 435356467 |
| 26 | 1306069401 |
| 27 | 2612138803 |
| 28 | 7836416409 |
| 29 | 15672832819 |
| 30 | 47018498457 |
| 31 | 94036996915 |
| 32 | 282110990745 |
[0,0,1,3,7,21,43,129,259,777,1555,4665,9331,27993, 55987,167961,335923,1007769,2015539,6046617, 12093235,36279705,72559411,217678233,435356467, 1306069401,2612138803,7836416409,15672832819, 47018498457,94036996915,282110990745] |