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 | 61 |
| 2 | 691 |
| 3 | 6991 |
| 4 | 69991 |
| 5 | 699991 |
| 6 | 6999991 |
| 7 | 69999991 |
| 8 | 699999991 |
| 9 | 6999999991 |
| 10 | 69999999991 |
| 11 | 699999999991 |
| 12 | 6999999999991 |
| 13 | 69999999999991 |
| 14 | 699999999999991 |
| 15 | 6999999999999991 |
| 16 | 69999999999999991 |
| 17 | 699999999999999991 |
| 18 | 6999999999999999991 |
| 19 | 69999999999999999991 |