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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 4 |
| 4 | 19 |
| 5 | 31 |
| 6 | 168 |
| 7 | 323 |
| 8 | 1859 |
| 9 | 4072 |
| 10 | 24403 |
| 11 | 59423 |
| 12 | 368488 |
| 13 | 980123 |
| 14 | 6275139 |
| 15 | 17998264 |
| 16 | 118858755 |
| 17 | 364059999 |
| 18 | 2478263856 |
| 19 | 8045642683 |
| 20 | 56418223739 |
| 21 | 192980878976 |
| 22 | 1392909382923 |
| 23 | 4995715059111 |
| 24 | 37083230363840 |
| 25 | 138896979832131 |
| 26 | 1059335618366171 |
[1,3,4,19,31,168,323,1859,4072,24403,59423,368488, 980123,6275139,17998264,118858755,364059999, 2478263856,8045642683,56418223739,192980878976, 1392909382923,4995715059111,37083230363840, 138896979832131,1059335618366171] |