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 | 9 |
| 2 | 89 |
| 3 | 789 |
| 4 | 6789 |
| 5 | 56789 |
| 6 | 456789 |
| 7 | 3456789 |
| 8 | 23456789 |
| 9 | 123456789 |
| 10 | 123456789 |
| 11 | -9876543211 |
| 12 | -209876543211 |
| 13 | -3209876543211 |
| 14 | -43209876543211 |
| 15 | -543209876543211 |
| 16 | -6543209876543211 |
| 17 | -76543209876543211 |
| 18 | -876543209876543211 |
| 19 | -9876543209876543211 |