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 | 20 |
| 1 | 41 |
| 2 | 83 |
| 3 | 167 |
| 4 | 335 |
| 5 | 671 |
| 6 | 1343 |
| 7 | 2687 |
| 8 | 5375 |
| 9 | 10751 |
| 10 | 21503 |
| 11 | 43007 |
| 12 | 86015 |
| 13 | 172031 |
| 14 | 344063 |
| 15 | 688127 |
| 16 | 1376255 |
| 17 | 2752511 |
| 18 | 5505023 |
| 19 | 11010047 |
| 20 | 22020095 |
| 21 | 44040191 |
| 22 | 88080383 |
| 23 | 176160767 |
| 24 | 352321535 |
| 25 | 704643071 |
| 26 | 1409286143 |
| 27 | 2818572287 |