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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 14 |
| 2 | 64 |
| 3 | 300 |
| 4 | 1418 |
| 5 | 6736 |
| 6 | 32098 |
| 7 | 153274 |
| 8 | 732980 |
| 9 | 3508800 |
| 10 | 16808758 |
| 11 | 80562042 |
| 12 | 386258512 |
| 13 | 1852391310 |
| 14 | 8885102252 |
| 15 | 42623064868 |
| 16 | 204486065796 |
| 17 | 981089277884 |
| 18 | 4707294583320 |
| 19 | 22586391528066 |
| 20 | 108375512842272 |
| 21 | 520021938034950 |
[1,14,64,300,1418,6736,32098,153274,732980, 3508800,16808758,80562042,386258512,1852391310, 8885102252,42623064868,204486065796,981089277884, 4707294583320,22586391528066,108375512842272, 520021938034950] |