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 | 7 |
| 3 | 11 |
| 4 | 20 |
| 5 | 41 |
| 6 | 85 |
| 7 | 172 |
| 8 | 343 |
| 9 | 683 |
| 10 | 1364 |
| 11 | 2729 |
| 12 | 5461 |
| 13 | 10924 |
| 14 | 21847 |
| 15 | 43691 |
| 16 | 87380 |
| 17 | 174761 |
| 18 | 349525 |
| 19 | 699052 |
| 20 | 1398103 |
| 21 | 2796203 |
| 22 | 5592404 |
| 23 | 11184809 |
| 24 | 22369621 |
| 25 | 44739244 |
| 26 | 89478487 |
| 27 | 178956971 |
| 28 | 357913940 |
| 29 | 715827881 |
| 30 | 1431655765 |
| 31 | 2863311532 |