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 | 1 |
| 3 | 5 |
| 4 | 24 |
| 5 | 215 |
| 6 | 2256 |
| 7 | 26925 |
| 8 | 339523 |
| 9 | 4456349 |
| 10 | 60149731 |
| 11 | 830492066 |
| 12 | 11681979493 |
| 13 | 166929456330 |
| 14 | 2417719752083 |
| 15 | 35429035715975 |