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 | 3 |
| 3 | 25 |
| 4 | 339 |
| 5 | 6721 |
| 6 | 179643 |
| 7 | 6166105 |
| 8 | 262308819 |
| 9 | 13471274401 |
| 10 | 818288740923 |
| 11 | 57836113793305 |
| 12 | 4693153430067699 |
| 13 | 432360767273547841 |
| 14 | 44794795522199781243 |
| 15 | 5176959027946049635225 |
| 16 | 662704551840482536170579 |