This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 6 | 1 |
| 7 | 189 |
| 8 | 16576 |
| 9 | 1023340 |
| 10 | 52563182 |
| 11 | 2445890678 |
| 12 | 108248782988 |
| 13 | 4693939818672 |
| 14 | 203214066766123 |
| 15 | 8891156436472127 |
| 16 | 396276632116578640 |
| 17 | 18084968846773765272 |
| 18 | 847923332620865268252 |
| 19 | 40927316768759272656876 |
| 20 | 2036183873275911481501656 |
| 21 | 104482592642320957223810448 |