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) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 13 |
| 4 | 50 |
| 5 | 203 |
| 6 | 1154 |
| 7 | 6627 |
| 8 | 49356 |
| 9 | 403293 |
| 10 | 3858376 |
| 11 | 33929377 |
| 12 | 460614670 |
| 13 | 5168544119 |
| 14 | 64518640406 |
| 15 | 946910125319 |
| 16 | 16124114481720 |
| 17 | 221243980745433 |
| 18 | 4261440137319852 |
| 19 | 68524390012831189 |
| 20 | 1477309421907315082 |