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 | 6 |
| 3 | 90 |
| 4 | 1050 |
| 5 | 11130 |
| 6 | 112266 |
| 7 | 1099098 |
| 8 | 10550826 |
| 9 | 99899514 |
| 10 | 936435786 |
| 11 | 8711707290 |
| 12 | 80572452714 |
| 13 | 741766408890 |
| 14 | 6803700252810 |
| 15 | 62219207836890 |
| 16 | 567597206875050 |
| 17 | 5167463468534010 |
| 18 | 46965976868507850 |
| 19 | 426262280218695450 |
| 20 | 3864157168469020650 |
| 21 | 34994228358927126330 |