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 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 119 |
| 6 | 708 |
| 7 | 4914 |
| 8 | 38977 |
| 9 | 347779 |
| 10 | 3447902 |
| 11 | 37600925 |
| 12 | 447332398 |
| 13 | 5765327905 |
| 14 | 80020698913 |
| 15 | 1189991560707 |
| 16 | 18876181370841 |
| 17 | 318136382176708 |
| 18 | 5677225148401090 |
| 19 | 106939954137362482 |
| 20 | 2120412050923152077 |
| 21 | 44145844897844974946 |
| 22 | 962859209130749461268 |