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 | 121 |
| 3 | 10201 |
| 4 | 22201 |
| 5 | 1002001 |
| 6 | 1022121 |
| 7 | 1212201 |
| 8 | 100020001 |
| 9 | 100220121 |
| 10 | 121022001 |
| 11 | 210221001 |
| 12 | 10000200001 |
| 13 | 10002200121 |
| 14 | 10020210201 |
| 15 | 10201202001 |
| 16 | 12100220001 |
| 17 | 100021020121 |
| 18 | 1000002000001 |
| 19 | 1000022000121 |
| 20 | 1000202010201 |