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 | 2 |
| 2 | 24 |
| 3 | 218 |
| 4 | 1776 |
| 5 | 13682 |
| 6 | 102024 |
| 7 | 745418 |
| 8 | 5374176 |
| 9 | 38400482 |
| 10 | 272709624 |
| 11 | 1928498618 |
| 12 | 13597146576 |
| 13 | 95668307282 |
| 14 | 672119557224 |
| 15 | 4717043931818 |
| 16 | 33080342678976 |
| 17 | 231867574534082 |
| 18 | 1624598900644824 |
| 19 | 11379821699045018 |