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 | 5 |
| 3 | 43 |
| 4 | 377 |
| 5 | 4291 |
| 6 | 58745 |
| 7 | 914803 |
| 8 | 15641897 |
| 9 | 298104451 |
| 10 | 6337624985 |
| 11 | 147137420563 |
| 12 | 3674045105417 |
| 13 | 98093008751011 |
| 14 | 2793940490888825 |
| 15 | 84812168406518323 |
| 16 | 2737609202984488937 |
| 17 | 93486719521251467971 |
| 18 | 3358396276982001106265 |
| 19 | 126434158646122122080083 |