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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 13 |
| 4 | 63 |
| 5 | 328 |
| 6 | 1797 |
| 7 | 10210 |
| 8 | 59607 |
| 9 | 355409 |
| 10 | 2155166 |
| 11 | 13250055 |
| 12 | 82402013 |
| 13 | 517453773 |
| 14 | 3276534510 |
| 15 | 20897024350 |
| 16 | 134118458191 |
| 17 | 865574280977 |
| 18 | 5613879001983 |
| 19 | 36571135386965 |
| 20 | 239187418784442 |
| 21 | 1569994174618799 |
| 22 | 10338925554033967 |
| 23 | 68288387553861826 |
[1,1,3,13,63,328,1797,10210,59607,355409,2155166, 13250055,82402013,517453773,3276534510, 20897024350,134118458191,865574280977, 5613879001983,36571135386965,239187418784442, 1569994174618799,10338925554033967, 68288387553861826] |