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 | 4 |
| 2 | 6 |
| 3 | 9 |
| 4 | 10 |
| 5 | 21 |
| 6 | 65 |
| 7 | 87 |
| 8 | 321 |
| 9 | 543 |
| 10 | 4321 |
| 11 | 8765 |
| 12 | 98765 |
| 13 | 654321 |
| 14 | 876543 |
| 15 | 7654321 |