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 | 98 |
| 3 | 987 |
| 4 | 9876 |
| 5 | 98765 |
| 6 | 987654 |
| 7 | 9876543 |
| 8 | 98765432 |
| 9 | 987654321 |
| 10 | 9876543210 |
| 11 | 98765432099 |
| 12 | 987654320988 |
| 13 | 9876543209877 |
| 14 | 98765432098766 |
| 15 | 987654320987655 |
| 16 | 9876543209876544 |
| 17 | 98765432098765433 |
| 18 | 987654320987654322 |
| 19 | 9876543209876543211 |
| 20 | 98765432098765432100 |
| 21 | 987654320987654320989 |