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 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 22 |
| 5 | 237 |
| 6 | 3961 |
| 7 | 99900 |
| 8 | 3757153 |
| 9 | 208571691 |
| 10 | 16945953790 |
| 11 | 1999844518737 |
| 12 | 340422874696873 |
| 13 | 83041703920313712 |
| 14 | 28850117307732482737 |
| 15 | 14191512425207950473867 |
| 16 | 9829313296102303971441502 |