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 | 9 |
| 2 | 33 |
| 3 | 105 |
| 4 | 321 |
| 5 | 969 |
| 6 | 2913 |
| 7 | 8745 |
| 8 | 26241 |
| 9 | 78729 |
| 10 | 236193 |
| 11 | 708585 |
| 12 | 2125761 |
| 13 | 6377289 |
| 14 | 19131873 |
| 15 | 57395625 |
| 16 | 172186881 |
| 17 | 516560649 |
| 18 | 1549681953 |
| 19 | 4649045865 |
| 20 | 13947137601 |
| 21 | 41841412809 |
| 22 | 125524238433 |
| 23 | 376572715305 |
| 24 | 1129718145921 |