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 | 6 |
| 2 | 17 |
| 3 | 38 |
| 4 | 81 |
| 5 | 166 |
| 6 | 337 |
| 7 | 678 |
| 8 | 1361 |
| 9 | 2726 |
| 10 | 5457 |
| 11 | 10918 |
| 12 | 21841 |
| 13 | 43686 |
| 14 | 87377 |
| 15 | 174758 |
| 16 | 349521 |
| 17 | 699046 |
| 18 | 1398097 |
| 19 | 2796198 |
| 20 | 5592401 |
| 21 | 11184806 |
| 22 | 22369617 |
| 23 | 44739238 |
| 24 | 89478481 |
| 25 | 178956966 |
| 26 | 357913937 |
| 27 | 715827878 |
| 28 | 1431655761 |
| 29 | 2863311526 |