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 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 7 |
| 5 | 41 |
| 6 | 260 |
| 7 | 1930 |
| 8 | 17463 |
| 9 | 200008 |
| 10 | 3026192 |
| 11 | 62212319 |
| 12 | 1742874972 |
| 13 | 65794989216 |
| 14 | 3314857545154 |
| 15 | 222226981778153 |
| 16 | 19858056830333695 |
| 17 | 2371636836808937036 |
| 18 | 378993965527624639893 |