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 | 3 |
| 2 | 7 |
| 3 | 21 |
| 4 | 67 |
| 5 | 213 |
| 6 | 667 |
| 7 | 2061 |
| 8 | 6307 |
| 9 | 19173 |
| 10 | 58027 |
| 11 | 175101 |
| 12 | 527347 |
| 13 | 1586133 |
| 14 | 4766587 |
| 15 | 14316141 |
| 16 | 42981187 |
| 17 | 129009093 |
| 18 | 387158347 |
| 19 | 1161737181 |
| 20 | 3485735827 |
| 21 | 10458256053 |
| 22 | 31376865307 |
| 23 | 94134790221 |
| 24 | 282412759267 |
| 25 | 847255055013 |
| 26 | 2541798719467 |
| 27 | 7625463267261 |