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| n | a(n) |
|---|---|
| 0 | 2 |
| 1 | 7 |
| 2 | 20 |
| 3 | 51 |
| 4 | 118 |
| 5 | 260 |
| 6 | 548 |
| 7 | 1121 |
| 8 | 2236 |
| 9 | 4373 |
| 10 | 8412 |
| 11 | 15960 |
| 12 | 29926 |
| 13 | 55547 |
| 14 | 102196 |
| 15 | 186567 |
| 16 | 338258 |
| 17 | 609532 |
| 18 | 1092328 |
| 19 | 1947829 |
| 20 | 3457724 |
| 21 | 6112873 |
| 22 | 10766328 |
| 23 | 18896880 |
| 24 | 33062090 |
| 25 | 57675631 |
| 26 | 100338836 |
| 27 | 174117915 |
| 28 | 301432558 |
| 29 | 520686644 |
| 30 | 897559340 |
| 31 | 1544207369 |
| 32 | 2651881468 |
| 33 | 4546263293 |
| 34 | 7781245524 |
[2,7,20,51,118,260,548,1121,2236,4373,8412,15960, 29926,55547,102196,186567,338258,609532,1092328, 1947829,3457724,6112873,10766328,18896880, 33062090,57675631,100338836,174117915,301432558, 520686644,897559340,1544207369,2651881468, 4546263293,7781245524] |