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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 11 |
| 3 | 84 |
| 4 | 738 |
| 5 | 7029 |
| 6 | 70570 |
| 7 | 735401 |
| 8 | 7879118 |
| 9 | 86249454 |
| 10 | 960434270 |
| 11 | 10845322135 |
| 12 | 123896322956 |
| 13 | 1429327711980 |
| 14 | 16628329185358 |
| 15 | 194858230552674 |
| 16 | 2297972689389087 |
| 17 | 27252117638208701 |
| 18 | 324797817830706494 |
| 19 | 3888255542301372866 |
| 20 | 46733817274361827340 |
| 21 | 563736664663891455990 |
[1,2,11,84,738,7029,70570,735401,7879118,86249454, 960434270,10845322135,123896322956,1429327711980, 16628329185358,194858230552674,2297972689389087, 27252117638208701,324797817830706494, 3888255542301372866,46733817274361827340, 563736664663891455990] |