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) |
|---|---|
| 4 | 1 |
| 5 | 13421 |
| 6 | 198134223 |
| 7 | 2898705467483 |
| 8 | 42442845454886086 |
| 9 | 621401842151984058606 |
| 10 | 9097949506151746630368210 |
| 11 | 133203071884610819994409432410 |
| 12 | 1950226184559914695131839252162415 |