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 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 9 |
| 5 | 21 |
| 6 | 27 |
| 7 | 57 |
| 8 | 81 |
| 9 | 111 |
| 10 | 189 |
| 11 | 243 |
| 12 | 333 |
| 13 | 441 |
| 14 | 729 |
| 15 | 777 |
| 16 | 999 |
| 17 | 1161 |
| 18 | 1701 |
| 19 | 2109 |
| 20 | 2187 |
| 21 | 2529 |
| 22 | 2709 |
| 23 | 2763 |
| 24 | 2793 |
| 25 | 2997 |