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 | 3 |
| 2 | 9 |
| 3 | 27 |
| 4 | 837 |
| 5 | 891 |
| 6 | 729 |
| 7 | 12393 |
| 8 | 277749 |
| 9 | 4782969 |
| 10 | 91703097 |
| 11 | 92293587 |
| 12 | 82019061 |
| 13 | 2674388259 |
| 14 | 10722885057 |
| 15 | 155747819547 |
| 16 | 19336668383673 |
| 17 | 667382013477 |
| 18 | 1019303306559 |
| 19 | 716912704223253 |
| 20 | 717162977859147 |
| 21 | 29411190301301847 |