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 | 20 |
| 2 | 1134 |
| 3 | 323940 |
| 4 | 350195076 |
| 5 | 1458203653116 |
| 6 | 23988036558291750 |
| 7 | 1573616297933972778420 |
| 8 | 412613600502090075171985440 |
| 9 | 432682737835397726783364117773760 |