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 | 2 |
| 2 | 7 |
| 3 | 40 |
| 4 | 326 |
| 5 | 3492 |
| 6 | 46558 |
| 7 | 744320 |
| 8 | 13889080 |
| 9 | 296459376 |
| 10 | 7125938790 |
| 11 | 190502850972 |
| 12 | 5607258255032 |
| 13 | 180198503713952 |
| 14 | 6278311585490032 |
| 15 | 235730921392184452 |
| 16 | 9489040823468191328 |
| 17 | 407662178549724426176 |