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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 61 |
| 3 | 223 |
| 4 | 1103 |
| 5 | 11341 |
| 6 | 65215 |
| 7 | 414651 |
| 8 | 3199929 |
| 9 | 21221319 |
| 10 | 144970307 |
| 11 | 1047053494 |
| 12 | 7264521347 |
| 13 | 50855971280 |
| 14 | 362028443523 |
| 15 | 2549685989975 |
| 16 | 18010279437728 |
| 17 | 127888224042540 |
| 18 | 905521633348229 |
| 19 | 6418498452393980 |
| 20 | 45573582767848687 |
[1,61,223,1103,11341,65215,414651,3199929, 21221319,144970307,1047053494,7264521347, 50855971280,362028443523,2549685989975, 18010279437728,127888224042540,905521633348229, 6418498452393980,45573582767848687] |