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) |
|---|---|
| 1 | 0 |
| 2 | 5 |
| 3 | 9 |
| 4 | 25 |
| 5 | 57 |
| 6 | 141 |
| 7 | 345 |
| 8 | 853 |
| 9 | 2097 |
| 10 | 5149 |
| 11 | 12633 |
| 12 | 31013 |
| 13 | 76161 |
| 14 | 187053 |
| 15 | 459369 |
| 16 | 1128053 |
| 17 | 2770065 |
| 18 | 6802301 |
| 19 | 16704249 |
| 20 | 41020357 |
| 21 | 100732833 |
| 22 | 247366989 |
| 23 | 607452297 |
| 24 | 1491704341 |
| 25 | 3663139761 |
| 26 | 8995478557 |
| 27 | 22089965337 |
| 28 | 54245756261 |
| 29 | 133209897153 |