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 | 1 |
| 1 | 1 |
| 2 | 6 |
| 3 | 49 |
| 4 | 542 |
| 5 | 7278 |
| 6 | 113824 |
| 7 | 2017881 |
| 8 | 39842934 |
| 9 | 865391422 |
| 10 | 20486717908 |
| 11 | 524816312106 |
| 12 | 14463876594476 |
| 13 | 426759508580416 |
| 14 | 13423937511765492 |
| 15 | 448515527244396873 |
| 16 | 15865571912065180326 |
| 17 | 592432249691301719190 |
| 18 | 23290086526099237126180 |
| 19 | 961614574423928988516286 |
| 20 | 41607005553456012247259844 |