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 | 63 |
| 4 | 189 |
| 5 | 729 |
| 6 | 729 |
| 7 | 2187 |
| 8 | 35721 |
| 9 | 45927 |
| 10 | 413343 |
| 11 | 413343 |
| 12 | 2657205 |
| 13 | 3720087 |
| 14 | 4782969 |
| 15 | 33480783 |
| 16 | 100442349 |
| 17 | 387420489 |
| 18 | 387420489 |
| 19 | 1162261467 |