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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 7 |
| 2 | 33 |
| 3 | 151 |
| 4 | 705 |
| 5 | 3367 |
| 6 | 16353 |
| 7 | 80311 |
| 8 | 397185 |
| 9 | 1972807 |
| 10 | 9824673 |
| 11 | 49005271 |
| 12 | 244672065 |
| 13 | 1222297447 |
| 14 | 6108298593 |
| 15 | 30531927031 |
| 16 | 152630937345 |
| 17 | 763068593287 |
| 18 | 3815084686113 |
| 19 | 19074648589591 |
| 20 | 95370918425025 |
| 21 | 476847618556327 |
[1,7,33,151,705,3367,16353,80311,397185,1972807, 9824673,49005271,244672065,1222297447,6108298593, 30531927031,152630937345,763068593287, 3815084686113,19074648589591,95370918425025, 476847618556327] |