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 | 0 |
| 2 | 12 |
| 3 | 345 |
| 4 | 6789 |
| 5 | 1011121314 |
| 6 | 151617181920 |
| 7 | 21222324252627 |
| 8 | 2829303132333435 |
| 9 | 363738394041424344 |
| 10 | 45464748495051525354 |
| 11 | 5556575859606162636465 |
| 12 | 666768697071727374757677 |
| 13 | 78798081828384858687888990 |