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 | 0 |
| 1 | 3 |
| 2 | 26 |
| 3 | 189 |
| 4 | 1284 |
| 5 | 8415 |
| 6 | 53934 |
| 7 | 340473 |
| 8 | 2125832 |
| 9 | 13163067 |
| 10 | 80974530 |
| 11 | 495513909 |
| 12 | 3019151628 |
| 13 | 18329137047 |
| 14 | 110933875542 |
| 15 | 669635727345 |
| 16 | 4032883785744 |
| 17 | 24239190315123 |
| 18 | 145427707041642 |
| 19 | 871139168383917 |
| 20 | 5210876275948820 |
| 21 | 31129900498786383 |
| 22 | 185755111545655806 |