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) |
|---|---|
| 2 | 1 |
| 3 | 3 |
| 4 | 12 |
| 5 | 67 |
| 6 | 512 |
| 7 | 5143 |
| 8 | 64988 |
| 9 | 995334 |
| 10 | 17948683 |
| 11 | 372703529 |
| 12 | 8759307844 |
| 13 | 229843336284 |
| 14 | 6660078541359 |
| 15 | 211201170221925 |
| 16 | 7274712426981184 |
| 17 | 270441300892307916 |
| 18 | 10791919593795653296 |
| 19 | 460087687818627367809 |