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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 5 |
| 3 | 38 |
| 4 | 281 |
| 5 | 2116 |
| 6 | 16222 |
| 7 | 126244 |
| 8 | 994860 |
| 9 | 7923456 |
| 10 | 63679869 |
| 11 | 515810606 |
| 12 | 4206733157 |
| 13 | 34515110876 |
| 14 | 284699216035 |
| 15 | 2359535370142 |
| 16 | 19638957026491 |
| 17 | 164089666469232 |
| 18 | 1375812276097887 |
| 19 | 11572233529290882 |
| 20 | 97619679434165691 |
| 21 | 825688568949199356 |
| 22 | 7001040129052461912 |
[1,5,38,281,2116,16222,126244,994860,7923456, 63679869,515810606,4206733157,34515110876, 284699216035,2359535370142,19638957026491, 164089666469232,1375812276097887, 11572233529290882,97619679434165691, 825688568949199356,7001040129052461912] |