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 | 7 |
| 3 | 18 |
| 4 | 39 |
| 5 | 82 |
| 6 | 167 |
| 7 | 338 |
| 8 | 679 |
| 9 | 1362 |
| 10 | 2727 |
| 11 | 5458 |
| 12 | 10919 |
| 13 | 21842 |
| 14 | 43687 |
| 15 | 87378 |
| 16 | 174759 |
| 17 | 349522 |
| 18 | 699047 |
| 19 | 1398098 |
| 20 | 2796199 |
| 21 | 5592402 |
| 22 | 11184807 |
| 23 | 22369618 |
| 24 | 44739239 |
| 25 | 89478482 |
| 26 | 178956967 |
| 27 | 357913938 |
| 28 | 715827879 |
| 29 | 1431655762 |