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 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 28 |
| 6 | 79 |
| 7 | 235 |
| 8 | 720 |
| 9 | 2254 |
| 10 | 7146 |
| 11 | 22927 |
| 12 | 74137 |
| 13 | 241461 |
| 14 | 790838 |
| 15 | 2603210 |
| 16 | 8604861 |
| 17 | 28549166 |
| 18 | 95027832 |
| 19 | 317229779 |
| 20 | 1061764660 |
| 21 | 3562113987 |
| 22 | 11976146355 |