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 | 6 |
| 2 | 108 |
| 3 | 1458 |
| 4 | 17496 |
| 5 | 196830 |
| 6 | 2125764 |
| 7 | 22320522 |
| 8 | 229582512 |
| 9 | 2324522934 |
| 10 | 23245229340 |
| 11 | 230127770466 |
| 12 | 2259436291848 |
| 13 | 22029503845518 |
| 14 | 213516729579636 |
| 15 | 2058911320946490 |
| 16 | 19765548681086304 |
| 17 | 189008059262887782 |
| 18 | 1801135623563989452 |
| 19 | 17110788423857899794 |