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 | 0 |
| 4 | 11 |
| 5 | 226 |
| 6 | 3597 |
| 7 | 55006 |
| 8 | 892791 |
| 9 | 15763270 |
| 10 | 305360481 |
| 11 | 6483720916 |
| 12 | 150200835113 |
| 13 | 3774756521566 |
| 14 | 102339496556342 |
| 15 | 2977913930684928 |
| 16 | 92579209306356230 |
| 17 | 3062597993515937128 |
| 18 | 107418845568842941190 |
| 19 | 3981908640735783136040 |
| 20 | 155550641755207044201203 |