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 | 19 |
| 2 | 97 |
| 3 | 907 |
| 4 | 9001 |
| 5 | 90001 |
| 6 | 900001 |
| 7 | 9000011 |
| 8 | 90000049 |
| 9 | 900000011 |
| 10 | 9000000001 |
| 11 | 90000000019 |
| 12 | 900000000013 |
| 13 | 9000000000059 |
| 14 | 90000000000077 |
| 15 | 900000000000019 |
| 16 | 9000000000000007 |
| 17 | 90000000000000011 |
| 18 | 900000000000000017 |