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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 6 |
| 2 | 41 |
| 3 | 321 |
| 4 | 2846 |
| 5 | 27961 |
| 6 | 297681 |
| 7 | 3371646 |
| 8 | 40065361 |
| 9 | 494281201 |
| 10 | 6279901766 |
| 11 | 81649478161 |
| 12 | 1080910639201 |
| 13 | 14511820543126 |
| 14 | 196956264035481 |
| 15 | 2695543342918241 |
| 16 | 37127978351861646 |
| 17 | 513895401953712521 |
| 18 | 7139331902125917361 |
| 19 | 99462520534916445006 |
| 20 | 1388616983941077336321 |
[1,6,41,321,2846,27961,297681,3371646,40065361, 494281201,6279901766,81649478161,1080910639201, 14511820543126,196956264035481,2695543342918241, 37127978351861646,513895401953712521, 7139331902125917361,99462520534916445006, 1388616983941077336321] |