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 | 2 |
| 1 | 11 |
| 2 | 101 |
| 3 | 13 |
| 4 | 137 |
| 5 | 9091 |
| 6 | 9901 |
| 7 | 909091 |
| 8 | 5882353 |
| 9 | 52579 |
| 10 | 27961 |
| 11 | 8779 |
| 12 | 99990001 |
| 13 | 1058313049 |
| 14 | 121499449 |
| 15 | 9091 |
| 16 | 69857 |
| 17 | 21993833369 |
| 18 | 999999000001 |
| 19 | 909090909090909091 |
| 20 | 5964848081 |
| 21 | 909091 |
| 22 | 1056689261 |
| 23 | 549797184491917 |