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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 37 |
| 3 | 305 |
| 4 | 2641 |
| 5 | 23525 |
| 6 | 213445 |
| 7 | 1961825 |
| 8 | 18205345 |
| 9 | 170195525 |
| 10 | 1600472677 |
| 11 | 15122515985 |
| 12 | 143457011569 |
| 13 | 1365435096485 |
| 14 | 13033485491077 |
| 15 | 124715953657025 |
| 16 | 1195966908404545 |
| 17 | 11490534389896325 |
| 18 | 110584004488276645 |
| 19 | 1065853221648055025 |
[1,5,37,305,2641,23525,213445,1961825,18205345, 170195525,1600472677,15122515985,143457011569, 1365435096485,13033485491077,124715953657025, 1195966908404545,11490534389896325, 110584004488276645,1065853221648055025] |