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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 8 |
| 6 | 14 |
| 7 | 47 |
| 8 | 195 |
| 9 | 837 |
| 10 | 3369 |
| 11 | 18578 |
| 12 | 136739 |
| 13 | 1165320 |
| 14 | 10402584 |
| 15 | 111016225 |
| 16 | 1486854375 |
| 17 | 24007190141 |
| 18 | 439055546197 |
| 19 | 9360979774817 |
| 20 | 239960578837701 |
| 21 | 7384548591700592 |
| 22 | 266113431327167571 |
[1,2,4,8,14,47,195,837,3369,18578,136739,1165320, 10402584,111016225,1486854375,24007190141, 439055546197,9360979774817,239960578837701, 7384548591700592,266113431327167571] |