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 | 4 |
| 3 | 9 |
| 4 | 18 |
| 5 | 40 |
| 6 | 80 |
| 7 | 176 |
| 8 | 352 |
| 9 | 769 |
| 10 | 1538 |
| 11 | 3343 |
| 12 | 6686 |
| 13 | 14477 |
| 14 | 28954 |
| 15 | 62505 |
| 16 | 125010 |
| 17 | 269216 |
| 18 | 538432 |
| 19 | 1157244 |
| 20 | 2314488 |
| 21 | 4966260 |
| 22 | 9932520 |
| 23 | 21282622 |
| 24 | 42565244 |
| 25 | 91096110 |
| 26 | 182192220 |
| 27 | 389515284 |
| 28 | 779030568 |
| 29 | 1664015246 |
| 30 | 3328030492 |