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 | 21 |
| 3 | 6617 |
| 4 | 12131 |
| 5 | 12441 |
| 6 | 114917 |
| 7 | 121221 |
| 8 | 124281 |
| 9 | 125121 |
| 10 | 145581 |
| 11 | 172631 |
| 12 | 182121 |
| 13 | 191213 |
| 14 | 211551 |
| 15 | 221211 |
| 16 | 221421 |
| 17 | 241213 |
| 18 | 293143 |
| 19 | 421531 |
| 20 | 421821 |