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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 63 |
| 2 | 705 |
| 3 | 6207 |
| 4 | 50113 |
| 5 | 389183 |
| 6 | 2965441 |
| 7 | 22380607 |
| 8 | 168132545 |
| 9 | 1260716095 |
| 10 | 9450356673 |
| 11 | 70882689087 |
| 12 | 532259536833 |
| 13 | 4002476458047 |
| 14 | 30145737916353 |
| 15 | 227429364793407 |
| 16 | 1718693633458113 |
| 17 | 13009919057854527 |
| 18 | 98641252341252033 |
[1,63,705,6207,50113,389183,2965441,22380607, 168132545,1260716095,9450356673,70882689087, 532259536833,4002476458047,30145737916353, 227429364793407,1718693633458113, 13009919057854527,98641252341252033] |