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 | 18 |
| 1 | 37 |
| 2 | 75 |
| 3 | 151 |
| 4 | 303 |
| 5 | 607 |
| 6 | 1215 |
| 7 | 2431 |
| 8 | 4863 |
| 9 | 9727 |
| 10 | 19455 |
| 11 | 38911 |
| 12 | 77823 |
| 13 | 155647 |
| 14 | 311295 |
| 15 | 622591 |
| 16 | 1245183 |
| 17 | 2490367 |
| 18 | 4980735 |
| 19 | 9961471 |
| 20 | 19922943 |
| 21 | 39845887 |
| 22 | 79691775 |
| 23 | 159383551 |
| 24 | 318767103 |
| 25 | 637534207 |
| 26 | 1275068415 |
| 27 | 2550136831 |
| 28 | 5100273663 |
| 29 | 10200547327 |
| 30 | 20401094655 |