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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 5 |
| 6 | 14 |
| 7 | 47 |
| 8 | 182 |
| 9 | 786 |
| 10 | 3774 |
| 11 | 19974 |
| 12 | 115236 |
| 13 | 720038 |
| 14 | 4846512 |
| 15 | 34950929 |
| 16 | 268836776 |
| 17 | 2197143724 |
| 18 | 19013216102 |
| 19 | 173672030192 |
| 20 | 1669863067916 |
| 21 | 16858620684522 |
| 22 | 178306120148144 |
| 23 | 1971584973897417 |
| 24 | 22748265125187632 |
[1,1,1,2,5,14,47,182,786,3774,19974,115236,720038, 4846512,34950929,268836776,2197143724,19013216102, 173672030192,1669863067916,16858620684522, 178306120148144,1971584973897417, 22748265125187632] |