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 | 4 |
| 2 | 9 |
| 3 | 19 |
| 4 | 38 |
| 5 | 69 |
| 6 | 134 |
| 7 | 289 |
| 8 | 520 |
| 9 | 1076 |
| 10 | 2134 |
| 11 | 4098 |
| 12 | 8376 |
| 13 | 16559 |
| 14 | 33020 |
| 15 | 66114 |
| 16 | 132119 |
| 17 | 263585 |
| 18 | 525765 |
| 19 | 1050309 |
| 20 | 2097946 |
| 21 | 4199226 |
| 22 | 8394235 |
| 23 | 16785959 |