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) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 4 |
| 3 | 9 |
| 4 | 79 |
| 5 | 799 |
| 6 | 9999 |
| 7 | 499999 |
| 8 | 19999999 |
| 9 | 999999999 |
| 10 | 199999999999 |
| 11 | 49999999999999 |
| 12 | 9999999999999999 |
| 13 | 7999999999999999999 |
| 14 | 7999999999999999999999 |
| 15 | 9999999999999999999999999 |