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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 6 |
| 4 | 22 |
| 5 | 64 |
| 6 | 227 |
| 7 | 776 |
| 8 | 2854 |
| 9 | 10455 |
| 10 | 39319 |
| 11 | 149787 |
| 12 | 579560 |
| 13 | 2257337 |
| 14 | 8887284 |
| 15 | 35287573 |
| 16 | 141013188 |
| 17 | 566875691 |
| 18 | 2292206719 |
| 19 | 9315490488 |
| 20 | 38020945055 |
| 21 | 155804714945 |
| 22 | 640940906466 |
| 23 | 2645526853223 |
| 24 | 10952645997032 |
| 25 | 45477822976693 |
| 26 | 189341279059823 |
| 27 | 790216314543537 |
| 28 | 3305546258574085 |
[1,1,3,6,22,64,227,776,2854,10455,39319,149787, 579560,2257337,8887284,35287573,141013188, 566875691,2292206719,9315490488,38020945055, 155804714945,640940906466,2645526853223, 10952645997032,45477822976693,189341279059823, 790216314543537,3305546258574085] |