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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 13 |
| 5 | 217 |
| 6 | 16693 |
| 7 | 21717363 |
| 8 | 2175145909081 |
| 9 | 283430597537694797281 |
| 10 | 3699017428454717709381715649628841 |
| 11 | 6290488320295607125006566146327310005599469877825552723 |