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 | 2 |
| 2 | 24 |
| 3 | 249 |
| 4 | 2499 |
| 5 | 24999 |
| 6 | 249998 |
| 7 | 2499999 |
| 8 | 24999999 |
| 9 | 249999998 |
| 10 | 2499999997 |
| 11 | 24999999997 |
| 12 | 249999999997 |
| 13 | 2499999999997 |
| 14 | 24999999999998 |
| 15 | 249999999999997 |
| 16 | 2499999999999996 |
| 17 | 24999999999999995 |
| 18 | 249999999999999995 |
| 19 | 2499999999999999995 |
| 20 | 24999999999999999996 |