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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 21 |
| 3 | 85 |
| 4 | 309 |
| 5 | 1245 |
| 6 | 4929 |
| 7 | 19493 |
| 8 | 78013 |
| 9 | 311345 |
| 10 | 1247009 |
| 11 | 4991273 |
| 12 | 19979925 |
| 13 | 79962153 |
| 14 | 319941873 |
| 15 | 1280018137 |
[1,5,21,85,309,1245,4929,19493,78013,311345, 1247009,4991273,19979925,79962153,319941873, 1280018137] |