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 | 15 |
| 4 | 86 |
| 5 | 492 |
| 6 | 2992 |
| 7 | 18172 |
| 8 | 110643 |
| 9 | 672267 |
| 10 | 4069122 |
| 11 | 24578785 |
| 12 | 147972210 |
| 13 | 889332713 |
| 14 | 5331980703 |
| 15 | 31924424199 |