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 | 2 |
| 3 | 3 |
| 4 | 6 |
| 5 | 17 |
| 6 | 70 |
| 7 | 401 |
| 8 | 2969 |
| 9 | 27140 |
| 10 | 296824 |
| 11 | 3805050 |
| 12 | 56375499 |
| 13 | 955491092 |
| 14 | 18372395618 |
| 15 | 397763836270 |
| 16 | 9625919876062 |
| 17 | 258564672432833 |
| 18 | 7659052858050807 |
| 19 | 248738123007194830 |
| 20 | 8812695551133726251 |
| 21 | 339191479636896892415 |
| 22 | 14131494196304254373334 |