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 | 5 |
| 4 | 43 |
| 5 | 518 |
| 6 | 8186 |
| 7 | 163356 |
| 8 | 3988342 |
| 9 | 116396952 |
| 10 | 3985947805 |
| 11 | 157783127673 |
| 12 | 7131072006829 |
| 13 | 364166073164914 |
| 14 | 20827961078794845 |
| 15 | 1323968417981743817 |
| 16 | 92917890994442697487 |
| 17 | 7157607311779373890120 |
| 18 | 602043767970637640566684 |