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 | 2 |
| 4 | 15 |
| 5 | 68 |
| 6 | 401 |
| 7 | 2179 |
| 8 | 23229 |
| 9 | 213332 |
| 10 | 2642772 |
| 11 | 38611992 |
| 12 | 723385584 |
| 13 | 16909827584 |
| 14 | 343510569552 |
| 15 | 9601049357952 |
| 16 | 305917702264416 |