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 | 1 |
| 2 | 23 |
| 3 | 345 |
| 4 | 4567 |
| 5 | 56789 |
| 6 | 67891011 |
| 7 | 78910111213 |
| 8 | 89101112131415 |
| 9 | 91011121314151617 |
| 10 | 10111213141516171819 |
| 11 | 1112131415161718192021 |
| 12 | 121314151617181920212223 |