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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | 16 |
| 3 | 58 |
| 4 | 204 |
| 5 | 714 |
| 6 | 2492 |
| 7 | 8682 |
| 8 | 30228 |
| 9 | 105226 |
| 10 | 366276 |
| 11 | 1274922 |
| 12 | 4437692 |
| 13 | 15446554 |
| 14 | 53765916 |
| 15 | 187147146 |
| 16 | 651418116 |
| 17 | 2267444842 |
| 18 | 7892485300 |
| 19 | 27472040138 |
| 20 | 95624259340 |
| 21 | 332847482970 |
| 22 | 1158570537292 |
| 23 | 4032735032490 |
| 24 | 14037083980308 |
| 25 | 48860072772074 |
| 26 | 170071413502180 |
| 27 | 591982043090090 |
| 28 | 2060562279111580 |
| 29 | 7172374493538586 |
| 30 | 24965494321148156 |
| 31 | 86899520830961866 |
| 32 | 302478557946941732 |
| 33 | 1052862859805769450 |
| 34 | 3664789362535367700 |
[1,4,16,58,204,714,2492,8682,30228,105226,366276, 1274922,4437692,15446554,53765916,187147146, 651418116,2267444842,7892485300,27472040138, 95624259340,332847482970,1158570537292, 4032735032490,14037083980308,48860072772074, 170071413502180,591982043090090,2060562279111580, 7172374493538586,24965494321148156, 86899520830961866,302478557946941732, 1052862859805769450,3664789362535367700] |