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 | 1 |
| 2 | 3 |
| 3 | 13 |
| 4 | 64 |
| 5 | 339 |
| 6 | 1885 |
| 7 | 10851 |
| 8 | 64109 |
| 9 | 386510 |
| 10 | 2368354 |
| 11 | 14706331 |
| 12 | 92337618 |
| 13 | 585239903 |
| 14 | 3739309053 |
| 15 | 24059542845 |
| 16 | 155756019048 |
| 17 | 1013801283133 |
| 18 | 6630587014935 |
| 19 | 43553555324502 |