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) |
|---|---|
| 3 | 1 |
| 4 | 3 |
| 5 | 22 |
| 6 | 255 |
| 7 | 3951 |
| 8 | 76468 |
| 9 | 1773108 |
| 10 | 48018645 |
| 11 | 1488656845 |
| 12 | 51989095026 |
| 13 | 2019934308294 |
| 14 | 86440374376447 |
| 15 | 4040615973961035 |
| 16 | 204882667497974040 |
| 17 | 11202622636253431336 |
| 18 | 657174516317371860777 |
| 19 | 41178215707421481322713 |