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 | 20 |
| 2 | 10022 |
| 3 | 10202 |
| 4 | 12002 |
| 5 | 12020 |
| 6 | 12200 |
| 7 | 20012 |
| 8 | 20102 |
| 9 | 20120 |
| 10 | 20201 |
| 11 | 20210 |
| 12 | 20220 |
| 13 | 21002 |
| 14 | 21200 |
| 15 | 22002 |
| 16 | 22010 |
| 17 | 22020 |
| 18 | 22100 |
| 19 | 22200 |
| 20 | 1210020 |
| 21 | 1210022 |
| 22 | 1212200 |
| 23 | 1220100 |
| 24 | 10222011 |
| 25 | 12200220 |
| 26 | 12202020 |
| 27 | 12210210 |
| 28 | 20010121 |
| 29 | 20010212 |