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 | 2 |
| 1 | 0 |
| 2 | 9 |
| 3 | 81 |
| 4 | 189 |
| 5 | 441 |
| 6 | 1449 |
| 7 | 10206 |
| 8 | 3969 |
| 9 | 12789 |
| 10 | 13041 |
| 11 | 35721 |
| 12 | 30429 |
| 13 | 194481 |
| 14 | 117369 |
| 15 | 115101 |
| 16 | 186921 |
| 17 | 2893401 |
| 18 | 273861 |