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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 11 |
| 4 | 44 |
| 5 | 155 |
| 6 | 647 |
| 7 | 2524 |
| 8 | 10851 |
| 9 | 44688 |
| 10 | 196029 |
| 11 | 834632 |
| 12 | 3713663 |
| 13 | 16168470 |
| 14 | 72696835 |
| 15 | 321575149 |
| 16 | 1457430579 |
| 17 | 6523572929 |
| 18 | 29751626175 |
| 19 | 134384963549 |
| 20 | 615987292496 |
| 21 | 2802342663867 |
| 22 | 12898952899310 |
| 23 | 59021474220361 |
| 24 | 272625261845824 |
| 25 | 1253368105759865 |
| 26 | 5806760449234618 |
| 27 | 26801640858939693 |
[1,1,4,11,44,155,647,2524,10851,44688,196029, 834632,3713663,16168470,72696835,321575149, 1457430579,6523572929,29751626175,134384963549, 615987292496,2802342663867,12898952899310, 59021474220361,272625261845824,1253368105759865, 5806760449234618,26801640858939693] |