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) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 15 |
| 4 | 52 |
| 5 | 198 |
| 6 | 796 |
| 7 | 3306 |
| 8 | 14042 |
| 9 | 60698 |
| 10 | 266235 |
| 11 | 1182315 |
| 12 | 5306085 |
| 13 | 24028162 |
| 14 | 109654887 |
| 15 | 503797703 |
| 16 | 2328343326 |
| 17 | 10816971516 |
| 18 | 50487762906 |
| 19 | 236635814984 |
| 20 | 1113297830297 |
| 21 | 5255647026534 |
| 22 | 24888156618738 |
| 23 | 118194065746758 |
| 24 | 562773777767295 |
| 25 | 2686074452484012 |