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) |
|---|---|
| 1 | 0 |
| 2 | 40 |
| 3 | 420 |
| 4 | 1721 |
| 5 | 14144 |
| 6 | 139563 |
| 7 | 3019035 |
| 8 | 24304266 |
| 9 | 206583092 |
| 10 | 3838101265 |